100% brand new and high quality Features: Compatibility: Converts a multi-speed hub to a single-speed wheel. Compatible with all Shimano or Sram 7 to 11 speed cassette-type hub bodies, for both mountain and road bikes. Note: It will not convert the hub into a fixed-gear (fixie), so 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, reaching a hardness of 18 degrees. Chain size compatibility: The sprocket works with chain widths from 1/2" x 3/32" to 1/2" x 11/128" (7-speed to 11-speed chains). You can use your original chain. Multiple sprocket tooth options allow you to achieve the ideal pedaling ratio. Perfect chain line: The kit includes single-speed spacers, lockring, and sprocket. A range of spacer sizes is provided to help achieve optimal chain alignment. Refer to the product video for more details. Package contents: Spacers: 2x 10mm, 1x 5mm, 4x 3mm Lockring: High-quality 6061 alloy Sprocket: Cro-mo steel construction for durability Specifications: Material: Stainless steel Color: Silver Teeth options: 12T, 13T, 14T, 15T, 16T (selectable) Processing technology: CNC cutting Packing size: Approximately 12 x 8 x 2 cm Applicable: Conversion of mountain or road bike multi-speed hubs to single-speed, compatible with 7/8/9/10/11-speed chains Notes: No retail packaging included. Allow 0–1 cm variation due to manual measurement. Due to differences in monitor displays, actual color may vary from the image. Package Includes: 1 x Single-Speed Bike Freewheel