Wolf Tooth Components Drop-Stop Chainring: 30T x 94 BCD 5-BoltThese rings are designed for Surly OD cranks, but are compatible with other 5 bolt 94 BCD cranks. 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 , and 12 speed chains, with the