How to use, pls follow the steps: 1. Press the nuts to the slots on both sides of the idler 2. Insert both bearings in the pulley,Be aware that bearings can out during assembly.(Layers might be visible in this part due to the geometry .The functionality and strength remain unaffected) 3. both bearings are inside the pulley 4. Insert the pulley in idler as shown in the picture. 5. Slide the shaft through the idler and pulley.Use reasonable force or you will BREAK the part. 6. Place your finger on the bearing and it can rotate freely. colour:Silver Material:metal Package Contents: 1 * pulley (with the lock screw) 1 * pulley (without the lock screw) 2 * pulley bearing 2 * Nuts 1 * pulley shaft 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.