Compatibility: Converts a multi-speed hub to a single-speed wheel. Works with all Shimano or SRAM 7 to 11 speed cassette-type hub bodies, for both mountain and road bikes. Note: This product does not convert the hub into a fixed gear; the hub remains a freewheel type. High-quality stainless steel: The sprocket is made of high-resistant stainless steel with strength and hardness twice that of standard 316 stainless steel. Hardness reaches 18 degrees. Chain compatibility: Fits chain widths from 1/2" x 3/32" to 1/2" x 11/128", suitable for 7-speed to 11-speed chains. Compatible with your original chain. Available in multiple tooth counts to achieve the ideal pedaling ratio. Specifications: Material: Stainless steel Color: Silver Teeth options: 12T, 13T, 14T, 15T, 16T (optional) Processing technology: CNC cutting Packing size: Approximately 12 x 8 x 2 cm (4.72 x 3.15 x 0.79 in) Application: Converts multi-speed mountain or road bike hubs to single speed, compatible with 7/8/9/10/11-speed chains Package includes: 1 x Single-Speed Bike Freewheel Note: No retail packaging included. Please allow 01 cm error due to manual measurement. Verify measurements before purchase. Due to differences in monitor displays, actual item color may vary slightly from images.