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 flywheel is made of high-resistant stainless steel, with strength and hardness twice that of standard 316 stainless steel, reaching 18 degrees in hardness. Chain size: The sprocket is compatible 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 ensures optimal chain alignment. Refer to the product video for additional details. Package includes: Spacers: 2x 10mm, 1x 5mm, 4x 3mm Hub lockring: High-quality 6061 alloy Sprocket: Cro-moly 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 (4.72 x 3.15 x 0.79 in) Applicable: Mountain and road bike multi-speed to single-speed conversion, compatible with 7/8/9/10/11-speed chains Notes: No retail packaging. Please allow 0–1 cm error due to manual measurement. Due to differences in monitor displays, the actual item color may vary slightly from the image. Package includes: 1 x Single-Speed Bike Freewheel