Pulley Block model Dual- Guide Rail Linear Rail SGB25-3 Speed Guider Locking Slider. Guide rail type: built-in double . Slider type: multi-wheel High-speed index: can run at high speed Installation method: 360° installation at application: Suitable for all high-speed, silent and high- equipment, woodworking table saws, Electronic machinery, industrial machinery, construction equipment, etc. Color: As Shown Material: Aluminum + Steel + Plastic Package Contents: 1 x pulley block Only the above package content, other products are not included. Note: Light reflection 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.