Race face direct mount cinch narrow wide chainringthe new next sl cinch system interface is made from 4mm plate 7075 t6 aluminum aerospace grade strength with their narrowwide tooth profiling to ensures ultimate chain retention specifications7075 t6 aluminum aerospace grade strengthstiff 4mm plate thickness to transfer loads without flexingcompatible for 9 10 and 11 speedattaches as part of the rf cinch system using parks bbt 22 bottom bracket toolsizes 26 28 30 32 34 36compatible w