1304 Stainless Steel: The bike freehub springs are made of 304 stainless steel, thus they have the characteristics of high strength and hardness, and they are durable for longer term. 2Integral Molding: The freehub springs are integrally formed, which features light weight, high strength, good toughness, not easy to break and firm. 3Repair Freehub Body: The bike freehub springs are used to repair the hub body and replace old or damaged pawl springs. They are ideal bike repair parts. 4Perfect Fit: The outer diameter of freehub spring is 20mm/0.79in and wire diameter is about 0.8mm/0.03in. They will perfect fit your bike freehub. 5Universal Designed: The bike freehub springs are used on many kinds of cassette hub drivers, carefully welding, and have complete functions.