and Reliable: Rear Derailleur Pulley is made from high strength plastic material, which can withstand large loads and impacts, offering a long service life.: Rear Derailleur Pulley Guide Roller is finely processed for smooth contact with the belt, ensuring stable drive, low noise, and reduced wear.Proper Positioning: Guide Wheel can accurately control the direction and position of the belt's movement, preventing it from deviating or falling off and ensuring stable drive.Wide Speed Range: Rear Derailleur Pulley features an adjustable conical structure, allowing for a range of speed changes to meet the drive needs of different devices.Wide Application: Rear Derailleur Pulley is easy to install without needing complex adjustments or maintenance, widely suitable for various mechanical equipment's drive systems such as textile machinery, packaging machinery, printing machinery, etc. Specification: Material: PlasticApplicable: Mountain Bike/Road Bike/Bike Size Chart: 11T: 4.4cmx4.4cmx0.8cm/1.73inchx1.73inchx0.31inch12T: 4.9cmx4.9cmx0.8cm/1.93inchx1.93inchx0.31inch13T: 5.3cmx5.3cmx0.8cm/2.09inchx2.09inchx0.31inch14T: 5.8cmx5.8cmx0.8cm/2.28inchx2.28inchx0.31inch Package Includes: 1 Rear Derailleur Guide Pulley Note: 1. Please allow slightly error due to manual measurement.2. Due to the difference between different monitors, the picture may not reflect the actual color of the item.3. Wish you a wonderful on line shopping!