Wolf Tooth Direct Mount Chainring - 38t, RaceFace CINCH Direct Mount, Drop-Stop B, 10/11/12-Speed Eagle and FlattopDesigned for Race Face CINCH cranks with removable spiders. This chainring features the patent pending asymmetrical Drop Stop tooth design for the best in wear life, mud clearance, and chain retention. Drop Stop chainrings are designed for use with 1x9, 1x10, 1x11 and 1x12 drivetrains Drop Stop FT is compatible with all 10 , 11 , and 12 speed chains (including SRAM Flattop 12 speed chains), with the exception of Shimano 12 speed chains Shimano 12