e*thirteen Direct Mount M Profile 10/11-speed Guide Ring 30t Narrow Wide, Direct mount rings fit e*thirteen TRS cranks and LG1 cranks with a removable spider Optimized dual width tooth profiles and chamfers provide greater chain retention than standard rings Exhaustive testing has yielded a long-wearing shape and finish to make sure your chain stays put 104bcd rings feature a flip-flop design that allows for a 49mm or 50mm chainline (30t rings use a Direct mount rings fit e*thirteen TRS cranks and LG1 cranks with a removable spider