Feature 1Used on rear derailleur for chain transportation and speed changing. 211T suits for 8/9/10/11 speed rear derailleur. 3Inner ceramic bearing is ultralight and owns high degree of lubrication, which can ensures its smooth working. 4Aluminum alloy construction is anti-rust and corrosion resistance, durable for long time use. 52 replaceable 4mm and 5mm bushing is included to enrich your installation choices.SpecificationFeatures: Used on rear derailleur for chain transportation and speed changing. 11T suits for 8/9/10/11 speed rear derailleur. Inner ceramic bearing is ultralight and owns high degree of lubrication, which can ensuresits smooth working. Aluminum alloy construction is anti-rust and corrosion resistance, durable for long timeuse. 2 replaceable 4mm and 5mm bushing is included to enrich your installation choices. A necessary accessary for your bicycle. Specification: Condition: Material: Aluminum Alloy Color: Red, Gold, Blue, Titanium Color, Black(Optional) Teeth: 11T Hole Diameter: Approx. 6mm / 0.24in(4mm and 5mm bushings are included) Size: Approx. 4 * 0.8cm / 1.6 * 0.3in Weight: Approx. 18g Packing List: 1 x Bike Rear Derailleur Pulley 2 x Bushings(4mm and 5mm) Note: Please allow slight size inaccuracy due to manual measurement and we appreciate for your understanding. .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; } Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.