Compatibility: Converts a multi-speed hub to a single-speed wheel. Works with all 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: The sprocket is made from high-resistance 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", suitable for 7-speed to 11-speed chains. Compatible with your existing 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: Convert 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 0–1 cm variation due to manual measurement. Ensure you are comfortable with this before purchasing. Due to differences in monitor displays, the actual product color may vary slightly from the image. Thank you!