Wolf Tooth Elliptical Direct Mount Chainring - 30t, SRAM 8-Bolt DM, 3mm Offset, Drop-Stop ST, Requires HG+ Chain, BlackWolf Tooth PowerTrac Elliptical direct mount rings use their proprietary PowerTrac design that has all the benefits of oval, but without the funky, uneven pedal stroke. These chainrings are designed for SRAM cranks with 8 bolt mounting and are specifically optimized for use with Shimano Hyperglide+ 12 speed chains and drivetrains. This chainring is equipped with the patented Drop Stop ST asymmetrical tooth design that provides the best in wear life,