Used Mitutoyo Tm-101 Toolmaker's Microscope With Mitutoyo Digital Readouts for sale (12,634)

Condition: excellent (used), For sale: a precision tool microscope from the renowned Japanese company Mitutoyo, model TM-101 (Code No. 176-901). This device is designed for dimensional, shape, profile, surface, and contour inspection in toolrooms, metrology laboratories, and quality control departments. Manufacturer: Mitutoyo Mfg. Co. Ltd., Japan. Type: TM-101. Digital readouts for X and Y axes with ABS and INC functions, preset, data output. Cross-travel measuring table with rotation and adjustment. Lighting functions: Surface, Contour, Main. Power supply: AC 220V, 50–60 Hz, 8 VA. Robust, stable industrial design. Very good condition, complete device, technically sound, ready for use. Ideal for measuring cutting tools, milling cutters, drills, inserts, inspecting precision components, and measuring contours, threads, and the geometry of parts. Iedoz Slcxjpfx Ag Ajtn

Condition: like new (used), Year of construction: 2021, functionality: fully functional, Equipment: documentation/manual, We offer for sale a professional digital microscope, the KEYENCE VHX-7000, a state-of-the-art device designed for detailed visual inspection, measurement, and analysis of materials and components. This microscope is ideal for industrial companies, laboratories, research institutions, quality control departments, and technical universities. 🔍 Main advantages and features: • ✅ High-resolution digital imaging • ✅ Advanced 2D and 3D surface imaging Itodpfxoz Ng Nts Ag Aon • ✅ Large depth of field and automatic focusing • ✅ Precise measurement of dimensions and surface analysis • ✅ Advanced lighting options and detail enhancement • ✅ Simple and intuitive operation • ✅ Capability for documentation, archiving, and evaluation of results • ✅ Suitable for quality control, research, and development 🏭 Application areas: • Automotive and mechanical engineering • Electrical engineering and electronics • Metallurgy and materials engineering • Quality control and analysis of manufacturing defects • Research, development, and laboratory measurements 📦 Device information: Manufacturer: KEYENCE Model: VHX-7000 Type: Professional digital microscope

Condition: excellent (used), functionality: fully functional, travel distance X-axis: 252 mm, travel distance Y-axis: 152 mm, workpiece weight (max.): 40 kg, input voltage: 110 V, type of input current: AC, total height: 1,155 mm, total length: 1,137 mm, space requirement width: 467 mm, overall weight: 155 kg, table length: 450 mm, table width: 146 mm, Equipment: lighting, Mitutoyo PH3500 Profile Projector Itjdpfxowr U A Do Ag Aon Used Mitutoyo PH3515F for sale in good condition. Manufacturer: Mitutoyo Type: PH3515F Built-in linear scale Magnification: 10x Display size: 353mm Digital angle measurement with 1' or 0.01° accuracy. Built-in linear scales for use with optional display counters. +/-0.1% or less (contour), +/-0.15% or less (surface) Working area range X-axis horizontal movement: 254 Y-axis vertical movement: 152 Table size: 450x146 mm Light source: Halogen bulb 24V 150W Suitable for thread pitch measurement – ​​No blurred or distorted image when the workpiece is tilted. Still image on the bright screen in the living room. Standard dual fiber optic illumination. 14" (353 mm) diameter protractor screen with crosshairs and stepped lines for easy alignment. Digital angle measurement with 1' or 0.01° accuracy. Durable workpiece table features linear scales for fast and accurate measurement. Height: 1155mm Length: 1137mm Width: 467mm Weight: 155kg

Condition: good (used), functionality: fully functional, Year of construction: 2007, TRUMPF TruMatic 7000 – 1300 Year of manufacture: 2007 Includes active dies! Includes Sheetmaster and Gripmaster Machine operating hours: 38,797 h Beam on-time: 38,149 h Laser power: approx. 4000 Watts Max. punching force: 220 kN Working area (laser operation): approx. 2540 x 1280 mm Working area: punching area: approx. 2540 x 1370 mm Control system: Bosch MTX compact Iodpfx Ajz Dumzjg Aetn Max. sheet thickness: approx. 8 mm Space requirement: approx. 7950 x 6700 mm Machine weight: approx. 23,000 kg Total connected load: 87 kVA

Condition: excellent (used), • Robust and stable aluminum base • Two guide rails for smooth movement • LCD display with clear readings • Functions: ON/OFF, ZERO, HOLD, PRESET Isdpfxsz Slbhj Ag Aotn • Original quality “Made in Japan” • Clearly visible serial number – guarantees authenticity • Very good condition – used equipment, tested • No play, accurate and repeatable measurements • Ready for use – no additional accessories required An excellent tool for workshops, tool rooms, quality control departments, and for precise measurements.

Condition: excellent (used), For sale: WAGNER FCA 500 universal milling machine in very good technical condition. This machine features robust German construction and is equipped with a 3-axis digital readout (DRO), which significantly facilitates precise machining operations. The mill is ideally suited for tool shops, single-part production, as well as maintenance and service work. Technical specifications: • Manufacturer: WAGNER Maschinen • Model: FCA 500 • Year of manufacture: 2004 • SINO digital readout – 3 axes (X,Y,Z) • Spindle speeds up to 2000 rpm • Power supply: 380 V • Frequency: 50 Hz • Total power: 6.5 kW Equipment: Itjdoz Slpxspfx Ag Aen • Vertical milling head • SINO digital readout • Variable speed control • Large work table with T-slots The machine is complete, in good technical condition, and shows normal signs of use.

Year of construction: 2016, condition: ready for operation (used), Life Technologies Amex 1000 Evos XL Core Digital Microscope Magnifications: 4x, 10x, 20x Dimensions: approx. 410mm x 320mm (D x W) Height: approx. 550mm Year of manufacture: 2016 You are welcome to arrange a viewing. We can organise cost-effective shipping for you! You will receive a proper invoice. For international customers, a net invoice can also be issued, provided you have a valid VAT ID number. Sale subject to prior sale. Iodpfx Asyx A Smsg Aetn Visit our shop to view more of our listings. The specified company names and trademarks are the property of their respective owners and are used for identification and product description purposes only. Deviations from technical data or errors in the item description may occur and are subject to change.

Condition: excellent (used), Year of construction: 2005, travel distance X-axis: 450 mm, travel distance Y-axis: 300 mm, travel distance Z-axis: 350 mm, spindle speed (max.): 2,500 rpm, quill stroke: 100 mm, For sale is an Emco tool milling machine, model FB-4. The machine was previously used exclusively for inter-company training purposes. Currently, two identical Emco FB-4 machines are still in stock. Tool Milling Machine V/H Manufacturer: Emco Model: FB-4 Year of manufacture: 2005 Control: Heidenhain ND-750 display Iodjyvra Ispfx Ag Ajtn Technical parameters: ----- • Travel X-Y-Z: 450 x 300 x 350 mm • Clamping surface: 800 x 400 mm • Tool holder: SK-40 • Tool clamping: hydraulic • Quill stroke: 100 mm • Milling head swivels ± 90° • Spindle speed: 50 – 2,500 rpm • Speed selection: 18 steps • Electric central lubrication • Machine lamp • Coolant system • Splash guard cabin (foldable) • Weight: 1,550 kg • Dimensions LxWxH in mm: ..1,485 x 1,500 x 1,700 mm Accessories: ----- • 4x machine leveling feet • Operating manual • Counter bearing for horizontal machining • Shaft for horizontal machining • Table enclosure (currently removed) • 10x SK-40 tool holders

Condition: used, ZEISS Type: DSM 962 The DSM 962 is a digitized scanning electron microscope equipped with an integrated 4 MB image memory, a 40 MB internal hard drive for image storage, and drives for external data and image storage. This enables quick and easy acquisition of information about the composition and morphology of sample surfaces, even down to the sub-micrometer range. With a magnification range of 5x to 300,000x, both the examination of macrostructures and microstructures is possible. Through special add-ons, the range of applications can be significantly expanded, allowing for analytical investigations in micro-areas of the surface, for example. The device can be operated using conventional switches as well as via the keyboard or mouse (optional). The electron optics and vacuum control are conventional. Image memory functions are controlled via the keyboard or mouse (optional). Centrally located on the control panel is a separate information screen for displaying the menus. This user manual is intended to serve as a guide for the user to achieve the best possible results with the device. The explanations have been kept as simple as possible in order to provide even less experienced users with the necessary knowledge. Magnification range: 20x to 300,000x at a 7 mm working distance Steps in a sequence of 1-2-3-5-10 Minimum magnification: 5x at a 50 mm working distance Itedpfx Agezdthyj Asn Resolution: 4 nm - guaranteed with a tungsten cathode at 30 kV, 6 mm working distance, untilted sample 25 nm - guaranteed with a tungsten cathode at 1 kV, 6 mm working distance, untilted sample 3.5 nm - guaranteed with an optimized LaB6 cathode at 30 kV, 6 mm working distance, untilted sample Scope of delivery: (DSM 962 with accessories as shown) Condition: used (Changes and errors in the technical data are subject to change!) Please inquire about transport options before purchasing. We would be happy to answer any further questions you may have by telephone.

Condition: ready for operation (used), Tool milling machine Deckel FP 2 / 3-axis digital display "NEW" / ORIGINAL CONDITION from a university Itodpfx Aeztdl Ieg Ajn -Travel ranges X/Y/Z 400x200x400mm -Table clamping surface 700x350mm -Speed range 40-2000 rpm -Feeds and rapid traverses in all three axes -Tool holder ISO 40 -Vertical / Horizontal milling attachment -Fixed swivel table -Coolant system -3-axis digital display "NEW" -Spindle nut X-axis "NEW" -Machine feet -Documentation Dimensions: LxWxH 1.5x1.7x1.8 meters / Weight 1600 kg Errors and omissions excepted.

Condition: good (used), functionality: fully functional, type of input current: AC, input voltage: 240 V, input frequency: 60 Hz, Used Keyence Digital microscope VHX 600E set in flightcase Manufacturer: Keyence Model: VHX 600 E Voltage: 100-240 VAC (50/60 Hz) Itsdov Dh Ryspfx Ag Ajn Set consisting of; – Digital microscope computer + power cable – Digital camera – Lens – Camera holder + mount – Keyboard + mouse – Console controller – Flightcase

Condition: ready for operation (used), Keyence VHX-500F Digital Microscope Digital Microscope Objectives: 0-50x ; 20-200x You are welcome to come by for a viewing. We are happy to arrange a cost-effective forwarding agent for you. organize! You will receive a proper invoice. A net invoice can also be issued for foreign customers. Prerequisite is a valid VAT number. Subject to prior sale. Visit our store and have a look at our other offers. Company names and trademarks are the property of their owners and are used only to identify and describe the products. Itedpfxounhkwj Ag Aon Deviations from technical data and errors in the description of the article may occur and are reserved.

Condition: ready for operation (used), Keyence IM 6020 Digital measuring projector Measuring microscope Microscope Keyence IM 6020 Keyence IM 6000 You are welcome to visit us for a viewing. We will be happy to arrange a cost-effective forwarding agent for you. Isdpfx Ageunhq Rj Aetn organize! You will receive a proper invoice. A net invoice can also be issued for foreign customers. Prerequisite is a valid VAT number. Subject to prior sale. Visit our store and have a look at our other offers. Company names and trademarks are the property of their owners and are used only to identify and describe the products. Deviations from technical data and errors in the description of the article may occur and are reserved

Condition: good (used), Morgana Plockmatic BM 2000S Digital Booklet-Making System The machine is in full working order and ready for production. Isdpfx Aoz S Uqqog Aotn A professional, automated booklet-making system from Morgana (part of the Plockmatic Group), designed for medium- to high-volume digital and offset print finishing environments. The system consists of: – Morgana VF602 sheet feeder with two bins, featuring air-assisted feeding – Morgana BM 2000S stitcher-folder unit, equipped with two wire-stitching heads – Morgana FTR 2000 trimmer – Morgana SQF 2000 square-fold unit BM 2000S Booklet-Making System Capacity: 1–25 sheets (80 gsm paper) Speed: up to 1,800 sets per hour Sheet size: max. 320 x 470 mm / min. 120 x 210 mm Paper weight: max. 300 gsm / min. 60 g/m² Stitching modes: saddle stitching, side stitching, and corner stitching Stitching heads: 2 Job storage: yes, 10 jobs Dimensions: including base and belt delivery unit – 1135 (H) x 1520 (W) x 680 (D) mm Weight: 161 kg VF602 Feeder Capacity: 2 x 270 mm / 2700 sheets (80 g/m² paper) Sheet size (width x length): max. 350 x 660 mm Sheet size (width x length): min. 120 x 210 mm Paper weight: max. 300 g/m² / min. 60 g/m² Throughput/speed: feeding speed (note: speed limited by the booklet-making unit) – up to 15,000 sheets per hour FTR 2000 Trimmer Capacity: 30 sheets (80 g/m² paper) Booklet length: max. after trimming 220 mm / min. after trimming 120 mm Booklet length: max. in pass-through mode (without trimming) 235 mm / min. in pass-through mode 105 mm Booklet width: max. 320 mm / min. 120 mm Speed: up to 1800 sets/hour Trim length: up to 15 mm Dimensions: including stand, 1100 (H) x 350 (W) x 595 (D) mm Weight: 83 kg SQF 2000 Squarefolder Capacity: 30 sheets (80 g/m²) Booklet (width x length): max. 320 mm x 228 mm / min. 120 mm x 105 mm Speed: up to 1800 sets/hour Dimensions: including stand, 1100 (H) x 350 (W) x 595 (D) mm Weight: 60 kg Touchscreen interface for quick format changes. Switch the machine to a different format with a single click.

Condition: used, functionality: fully functional, type of input current: AC, input voltage: 240 V, Equipment: type plate available, Used Keyence Digital Microscope VHX 900/950F Set in Flightcase Manufacturer: Keyence Model: VHX 900/950F Voltage: 100-240 VAC (50/60 Hz) Set consists of: – Digital microscope + power cable – Digital camera – Lens (Keyence VH-Z20R) Itodpfxjv A Upto Ag Aen – Camera holder + mount – Keyboard + mouse – Console controller – Flightcase

Condition: ready for operation (used), Carl Zeiss Primo Vert Digital Microscope – Digital Measuring Microscope Objectives: 4x, 10x, 20x, 40x Dimensions: approx. 261mm x 550mm x 494mm Weight: 11 kg For technical specifications, please refer to the images. You are welcome to arrange a viewing appointment. We are happy to organize affordable shipping for you! Itsdsyx Dafjpfx Ag Asn You will receive a proper invoice. For international customers, a net invoice can be provided, subject to a valid VAT identification number. Subject to prior sale. Visit our shop to see more of our offers. The specified company names and trademarks are the property of their respective owners and are used for identification and description purposes only. Deviations in technical data and errors in the description of the article may occur and are subject to change.

Year of construction: 2005, condition: used, functionality: unexamined, machine/vehicle number: X-1802, Used Andor Ixon DV885JCS-VP microscope camera in a case. Manufacturer: Andor Technology Model: (Ixon) DV885JCS-VP Itodpfx Agszgtnfe Aon Includes software, power supply, connection cables, and system PCBs.

Condition: used, NC universal tool milling machine MAHO type MH 700 P with HEIDENHAIN TNC 121 linear control . 71247 Circuit diagram no. ET 226 Built in 1979 Travel paths X: 600 mm, Y: 400 mm, Z: 400 mm Table size 900 x 500 mm Spindle mount ISO 40 Spindle speed 40-2000 rpm, 18 steps Feed rate X, Z-axis 1 - 600 mm/min, continuously variable Feed rate Y 1 - 300 mm/min, continuously variable Rapid traverse X, Z-axis 1.5 m/min Rapid traverse Y-axis 0.75 m/min Vertical spindle travel 80 mm Horizontal spindle travel 80 mm Spindle drive 4 kW Power supply 380 V, 50 Hz, 10 kW Itedswd Szbspfx Ag Asn - HEIDENHAIN TNC 121 NC linear control - Vertical milling head with automatic Quill feed - Hydro-mechanical tool clamping - Coolant system in the machine base - Universal built-in rotary table, swiveling and tilting via threaded spindles +/- 30° - Universal built-in rotary table with manual transverse adjustment of 200 mm - Universal built-in rotary table with 360° rotation function and hydraulic clamping - Rotary table with direct indexing 72 x 5° and indirect indexing via hole plate 1:120 = 1 rev = 3° - Pivoting control panel - Central lubrication system - Electrical diagram Space requirement L x W x H 2000 x 1650 x 2250 mm Weight approx. 2800 kg Good condition

Condition: good (used), Internal Item No.: 25110 Universal Milling Machine Deckel FP3 Machine No.: 2482 Itjdpfjyb Su Usx Ag Aon + 3-axis digital readout + Safety guard with switch (UVV) + Machine lamp + Various SK40 tool holders and collet set (S20x2) Milling table: 800 x 420 mm Spindle taper: SK40 Max. speed: 2000 rpm Drive power: 3 kW Travel X/Y/Z: 500/300/400 mm Dimensions (LxWxH): 1400 x 1500 x 1800 mm Weight: approx. 1500 kg The machine is fully functional and can be demonstrated under power by arrangement in a heated storage area of over 500 m².

Condition: new, VHX-600E, Keyence Digital Microscope - New Model: VHX-600E Itsdpfx Agsq S Ti Es Ajn Type: VHX-600E Condition: New

Condition: excellent (used), For sale: Professional automatic Vickers hardness tester Mitutoyo HV-100, made in Japan, in excellent technical and visual condition. The device is equipped with the AUTOVICK automatic measurement system and the Mitutoyo Vision Unit, enabling fast, repeatable and fully automatic hardness measurements without operator subjectivity. Intended for measurement laboratories, quality control departments, manufacturing plants, automotive, aerospace, and toolmaking sectors. —— Key information • Measurement method: Vickers (HV) • Model: HV-100 (series HV-100B / HV-100C / 100D) • Load range: up to 100 kgf • Automatic AUTOVICK system • Integrated Mitutoyo Vision Unit • Automatic impression recognition and HV calculation • Made in Japan • Power supply: 230 V • Stable, heavy-duty laboratory construction —— Technical condition • Device operational and complete • Very good visual condition • Regularly used in an industrial environment • Last technical inspection: 2020 • Ready for immediate operation after connection —— Included in the set Ijdpfjz Slltex Ag Ajtn • Mitutoyo HV-100 hardness tester • Vision Unit (measuring camera) • AUTOVICK automatic system • Set of weights • Original accessories and holders • Transport cases with equipment • Original Mitutoyo documentation and manuals • Weight: 65 kg

Condition: excellent (used), Year of construction: 2025, functionality: fully functional, machine/vehicle number: 5B0S000433, No minimum price – guaranteed sale to the highest bidder! The new price of the microscope was approximately €100,000! Further technical details can be found in the attached data sheet! TECHNICAL DETAILS Maximum magnification: x1000 Camera VHX-7100 Sensor size: 1/1.7 inch Sensor type: 12.22-megapixel CMOS sensor Total pixels (H x V): 4,168 × 3,062 Virtual pixels (H x V): 4,024 × 3,036 High speed (H x V): 2,048 × 1,536 High resolution, 4K mode OFF (H x V): 2,880 × 2,160 High resolution, 4K mode ON (H x V): 4,000 × 3,000 Isdpozb Eixofx Ag Astn High resolution (H x V): 12,000 × 9,000 Electronic shutter speed: 1/30, 1/60, 1/120, 1/250, 1/500, 1/1,000, 1/2,000, 1/5,000, 1/9,000, 1/19,000 Supercharge shutter speed: 0.01-s steps from 0.03 to 4 s LCD monitor Size: 27-inch color LCD Screen size (H x V): 596.16 × 335.34 mm Pixel pitch (H x V): 0.15525 × 0.15525 mm Number of pixels (H x V): 3,840 × 2,160 Display colors: approx. 1.07 billion Viewing angle: ±89° horizontal, ±89° vertical VHX-S770E stand Travel range of the XY stage: ±50 mm Size of the XYθ stage (surface): 233 × 185 mm Speed of the motorized XY stage max.: 20 mm/s Travel range of the Z stage: 49 mm Load capacity: 5 kg Weight: 25.3 kg MACHINE DETAILS Connection: Digital Dimensions & Weight Dimensions without protruding parts (W x H x D): 635 x 450 x 132 mm Weight of the control unit: 10.8 kg EQUIPMENT KEYENCE VHX-X1 microscope unit Control console VHX-AX1D Processing unit OP-88885 Camera unit VHX-7100 Objective lens VH-Z00T High-performance objective lens VH-Z100 Motorized revolving head Motorized precision stand VHX-S770E Large motorized XY stage Software module VHX-H6M Ring light and illumination adapter OP-88164 3D profile measurement Manufacturer documentation Original accessories

Condition: used, Technical details: x-axis: 1000 mm z-axis: 600 mm diameter: - mm measuring range Y-axis: 972 mm interface: RS-232 tool taper: - weight: 40 kg Itjdozbqypepfx Ag Asn power consumption: 100 Watt Floor Space WxD: 1,2 x 0,8 m Mitutoyo Linear Height 600 Height Gauge with Wenzel Precision Granite Surface Plate (Optional) The granite surface plate is not included in the sale but can be purchased separately. For sale is a high-quality Mitutoyo Linear Height 600 digital height gauge, designed for accurate 2D measurement tasks in quality control, toolmaking, manufacturing and inspection departments. Mitutoyo Linear Height 600 ·Precision digital height measuring instrument ·Measuring range: 600 mm ·RS232 data output ·Made in Japan ·High accuracy and repeatability ·Ideal for quality assurance and manufacturing environments Measurement Capabilities ·Height measurements ·Internal and external dimensions ·Hole center distances ·Center point determination ·Step measurements ·Diameter measurements ·2D measurement applications ·Angle measurements (with optional accessories) Optional: Wenzel Precision Granite Surface Plate ·Size: 1000 × 630 mm ·Manufacturer: Wenzel Precision ·Inspection date: 07.11.1989 ·Permissible flatness deviation: 0.008 mm ·Measured flatness deviation: 0.005 mm ·Weight: approx. 280 kg An excellent solution for toolrooms, quality control laboratories, precision engineering and manufacturing facilities. *

Condition: like new (used), Year of construction: 2021, overall weight: 1,200 kg, total height: 2,200 mm, total length: 2,600 mm, total width: 1,400 mm, power: 2 kW (2.72 HP), For Sale: Brand: GHD Hartmann Model: Hartmann Clip EC 101 IS Clip Machine EC: Easy Clean Year: 09/2021 Suitable for plastic/paper clips. This closing unit features a compact machine frame and its own pulse-controlled drive. It integrates easily with vertical or horizontal packaging machines (bagging machines). Thanks to intermittent operation, it is ideal for manual loading. Synchronization with the upstream filling machine is not required. Bags are discharged via a cross conveyor belt at an angle of 20°, 30°, or optionally 45° and 60°. A built-in vacuum unit at the closing station extracts excess air from the bags for a neat, tight package. The product bags are then clipped and discharged. Option included: HPD printer for printing a date onto the plastic clip. Specifications: - Adjustable speeds - Capacity up to approx. 3,600 units per hour - Product dimensions: Length: up to 400 mm, Width: up to 220 mm, Height: up to 120 mm Itodpfxsxrf T Ds Ag Ajn - Siemens S7-1500 control system - SEW drives - Pneumatics: Festo - Stainless steel safety covers and guides The machine can be inspected and viewed on location. If you have any questions or require further information, please feel free to contact us. Kind regards, Leo Holland

Condition: used, Year of construction: 2004, Mitutoyo CRYSTA-Apex C7106 – used CNC coordinate measuring machine with a gantry design, professionally inspected and fully functional. The proven C-series from Mitutoyo stands for measurement stability on a granite base – ideal for precise 3D measuring tasks in the metrology lab. Technical data: - Measuring range: 700 x 1000 x 600 mm - Control system: UC-200H - Software: MCOSMOS-1 V4 - Probe system: Renishaw PH10M Equipment & accessories: - Renishaw PH10M rotary/tilting head - Renishaw TP200 probe system - Renishaw HCU1 hand control unit - Mitutoyo calibration certificate 08/2026 (WK-2060334-26) Included in the scope of supply: - Coordinate measuring machine CRYSTA-Apex C7106 - Renishaw PH10M rotary/tilting head - Renishaw TP200 probe system - Renishaw HCU1 hand control unit - Computer system with MCOSMOS-1 V4 - Mitutoyo calibration certificate 08/2026 Not included in the scope of supply: Itjdpsz Tffnofx Ag Asn - Automatic probe changer / probe changing rack Condition: used, inspected – fully functional. Year of manufacture: 2004. Procedure: Inspection by appointment. Disassembly and loading will be carried out by us, transport on request. Location: Leonberg, Germany. Kneissl Messtechnik GmbH – your specialist for coordinate measuring technology with an accredited DAkkS calibration service. Installation, training, and instruction are optional.