Widely used for digital 3D coordinate measuring equipment such as precision equipment or special machinery industry Suitable for kinds of electronic equipment/guide bar, drive shaft, and pillar Bearing Pillow Block have a certain bearing capacity, can hold in ordinary precision rack, strong adaptability. Smooth 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 : Outer diameter: 8mm or 0.31inch Length: 200mm or 7.87inch Specification of Linear Rail Support Guide Shaft Bearing : 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 diameter 8mm) Pacakge Size:45 x 35 x 30mm/1.77 x 1.38 x 1.18 inch Specification of Linear Ball Bearing: Inner Diameter: 8mm/0.315 inch Length: 34.5mm/1.36 inch Package Contents: 4 * Linear Motion Ball Bearing 4 * Rail Support Guide 2 * Linear Shaft Optical Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.