Mika Metals Racing chains are made of high quality brushings to reduce friction between plates. They are built to withstand high impact loads in the worst conditions. Their lightweight combined with high tensile strength creates the ultimate racing chain. The 415 Factory Series chain has 120 links. 415 chains fit all KTM 50cc bikes, and modified (must buy 415 sprockets) Cobra 50cc bikes. We HIGHLY recommend the use of a master link press to press on the master link as the chains are designed not to have any slack.