Description:This bike single speed cassette cog made of high quality steel material with anti-rust plating- high strength, strong and solid for long time using The set includes 1×9mm spacer, 1×4mm spacer, 1× 1

8mm spacer, 1 speed cassette, end ring and lock ring for convenient using Fits for 10/11 Speeds HG hubs conversion Designed for fixed gear conversion for 6-Bolt disc hubs single speed Lightweight won't add more burdens to your bike and scientific design increases contact area to protect hub bodySpecification:Fits for 10/11 Speeds HG hubs conversion Teeth: 17T / 18T / 19T / 20T / 21T / 22T / 23TPackage Includes:1 Set Cassette Cog