Compatibility: Converts a multi-speed hub to a single-speed wheel. Works with Shimano and SRAM 7 to 11 speed cassette hubs, for both mountain and road bikes. Note: This product does not convert the hub into a fixed-gear (fixie) setup; the hub remains a freewheel type.High-quality stainless steel construction: The sprocket is made from high-resistant stainless steel with strength and hardness twice that of standard 316 stainless steel, achieving a hardness of 18 degrees.Chain compatibility: Fits chain widths from 1/2" x 3/32" to 1/2" x 11/128". Compatible with 7-speed to 11-speed chains. You can use your original chain. Multiple sprocket tooth options allow you to achieve the ideal gear 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 note: Allow 01 cm variation due to manual measurement. Ensure you are comfortable with this before purchasing. Due to differences in monitor displays, actual color may vary slightly from the image. Thank you!