Quick shifting performance: the will keep you rolling and make your bike ride so smooth that you will anymore! Complete set: the derailleur pulleys include a complete set of different bushings to compatible for several shifting systems. It has stronger durability. Recommended Use: road cycling Light weight, stylish appearance, strong compatibility. Make your bike chain runs through the rear derailleur smoother and quieter than before. Type:13T Colour:Black Material:Plastic Package Contents: 4 * Bicycle guide wheel 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.