Narrow Wide tooth profile for better chain retention- Forged and machined 7000 series alloy with hard black anodizing for durability- Works with 1x10/11/12sp Shimano, KMC and SRAM Eagle, Flat and T-type chains- Must use a 'clutch' 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