Wolf Tooth Components Drop-Stop Chainring: 30T x 94 4-BoltDesigned to fit 94 BCD 4 Bolt cranks such as the SRAM X1 crank, these rings will provide maximal chain retention and minimal noise. These rings feature the patent pending Drop Stop asymmetrical tooth design for the best in wear life, mud clearance, and chain retention. Features Wolf Tooth's Drop Stop tooth design for maximum chain retention Drop Stop chainrings are designed for use with 1x9, 1x10, 1x11 and 1x12 drivetrains Compatible with all 10 , 11