Material: Made of high-quality iron, high performance and heat resistance, tough and long lasting. Size: Teeth: 22T. Chain compatibility: 1/2" x1 / 8". Easy Installation: Teyssor Single-Speed Freewheel is lightweight and compact, easy to be installed or removed on the bicycle. Bearings: Quality ball bearings which rolls smoothly. Compatibility: Compatible with standard threaded bicycle rear hub. Suitable for any single-speed bikes.