【Maximum durability | High efficiency】 【Direct Mount | Easy upgrade】 KMC created the "Chain Mate" where the chainring roller seats between teeth are matched to chain rollers for exceptional component engagement. Made of High Tensile Steel, the Chainring structure enhances retention with an optimized tooth design to hold the rollers in place, significantly preventing chain drop while also reducing friction associated with traditional narrow/wide designs. In addition, the tooth is vertically asymmetrical to avoid interference while at extreme chain angles to the cassette. - 34T, Chain line: 52mm - 38T, Chain line: 47.5mm, 50mm, 52mm - 40T, Chain line: 52mm