Durable and Reliable: Rear derailleur pulley is made from high-strength plastic material, capable of withstanding heavy loads and impacts, providing a long service life. The rear derailleur pulley guide roller is precisely processed for smooth chain contact, ensuring stable performance, low noise, and reduced wear. Proper positioning: The guide wheel accurately controls the chain's direction and position, preventing misalignment or derailment, ensuring consistent drive performance. Wide speed range: The rear derailleur pulley features an adjustable conical design, enabling various speed settings to meet the drive requirements of different applications. Wide application: The rear derailleur pulley is easy to install without complex adjustments or maintenance, making it suitable for use in various mechanical drive systems such as textile, packaging, and printing machinery. Specification: Material: Plastic Applicable: Mountain bike, road bike, bicycle Size Chart: 11T: 4.4cm x 4.4cm x 0.8cm / 1.73in x 1.73in x 0.31in 12T: 4.9cm x 4.9cm x 0.8cm / 1.93in x 1.93in x 0.31in 13T: 5.3cm x 5.3cm x 0.8cm / 2.09in x 2.09in x 0.31in 14T: 5.8cm x 5.8cm x 0.8cm / 2.28in x 2.28in x 0.31in Package Includes: 1 x Rear Derailleur Guide Pulley Note: 1. Please allow slight measurement deviation due to manual measurement. 2. Due to monitor display differences, the actual color may vary slightly from the image.