Widely used for digital 3D coordinate measuring equipment such as precision equipment or machinery industry Suitable for kinds of electronic equipment/guide bar, drive shaft, and pillar Pillow Block have a certain capacity, can hold in precision , strong adaptability. moving, low friction, high rigidity and long working life. They are good abrasion resistance, not easy to rust, high precision and good strength. Color: Silver Material: aluminum alloy Specifications of Steel Linear Shaft Optical Axis : Outer diameter: 8mm or 0.31inch Length: 200mm or 7.87inch Specification of Linear Rail Support Guide Shaft : Product Size:42 x 32 x 11mm/1.65 x 1.26 x 0.43 inch Inside Diameter:8mm/0.31 inch (Applicable to the optical axis diameter 8mm) Pacakge Size:45 x 35 x 30mm/1.77 x 1.38 x 1.18 inch Specification of Linear Ball : Inner Diameter: 8mm/0.315 inch Length: 34.5mm/1.36 inch Contents: 4 * Linear Motion Ball 4 * Rail Support Guide 2 * Linear Shaft Optical Axis Only the above content, other are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.