Helix Core e*spec Direct Mount Chainrings feature our narrow-wide tooth profile, for reliable chain retention and an extra long wear life. Helix Core e*spec rings are cold-formed from steel and then heat-treated to provide excellent durability and toughness, all at a price that's easy on your wallet.FeaturesLong-lasting and economical steel construction.M4 narrow-wide tooth profile for excellent chain retention and Shimano®/SRAM® drivetrain compatibility.Compatible with SRAM® T-Type® chains.SpecificationsChainline: Bosch®: 53/55mm options with included spacer; TQ®: 55mm; Shimano®: 55mmColor: BlackCompatibility: Bosch® SX / Gen4 CX, TQ® HPR50, Shimano EP8®Material: 4040 SteelSize: Bosch®: 34T, 36T; TQ®: 32T; Shimano®: 32TMfr Claimed WeightBosch®: 189gTQ®: 94gShimano®: 113g