MTB Single Speed Cassette One Speed Cog 1Speed Gear Fixed 13T-22T HG Freewheel
Specification: 13T 14T 15T 16T 17T 18T 19T 20T 21T 22T. The flywheel is made of high-resistant stainless steel, whose strength and hardness are twice that of ordinary 316 stainless steel, and the hardness reaches 18 degrees.