Narrow Wide tooth profile for better chain retention. Forged and machined 7000 series alloy with hard black anodizing for durability. Works with 1×10/11/12sp Shimano, KMC and SRAM Eagle, Flat and T-type chains. For Gen2 (G2) Praxis cranks (noted on crank arm) and SRAM mountain cranks; +3mm offset = 52mm chainline, 0mm offset= 55mm chainline. For original Gen1 Praxis cranks;+3mm offset = 49mm chainline, DM-B 0mm offset=55mm chainline. Must use a aclutcha type rear derailleur. Ex: Shimano Shadow or SRAM Type2 . Shimano compatible with both mechanical and Di2 Shimano 10/11/12sp. SRAM compatible with both mechanical and wireless SRAM 10/11/12sp. In rough terrain, or just for pure security, use of an upper guide recommended. Unauthorized online sales prohibited by manufacturer