Wolf Tooth Direct Mount Chainring - 42t, SRAM Direct Mount, For SRAM 3-Bolt, 6mm Offset, Drop-Stop, Flattop Compatible, BlackDirect mount rings designed for SRAM cranks with removable spiders. This chainring is equipped with the patent pending Drop Stop asymmetrical tooth design for the best in wear life, mud clearance, and chain retention. Product Details: Compatible with all 10 , 11 , and 12 speed chains, with the exception of Shimano 12 speed chains Drop Stop chainrings are designed for use with 1x9, 1x10, 1x11 and 1x12 drivetrains If using a 9 speed drivetrain, use a 10