Designed to fit 4-arm 110 Asymmetric BCD Shimano Road Cranksets. Its proprietary design has an ovality of 10% and a timing of 112 degrees after top dead center which provide the beneifits of an oval ring such as greater rear wheel traction without the traditional downsides of oval rings. These rings feature the patent pending Drop-Stop asymmetrical tooth design for the best in wear life, mud clearance, and chain retention. Not compatible with 9 speed chains. The simplest way to explain the way these rings feel is having 2 teeth less in the weak part of your pedal stroke and 2 teeth more where you have the most power. Features Wolf Tooth’s Drop-Stop tooth design for maximum chain retention. Optimized for use with 10, 11, and 12 speed chains. Color: Black. Material: Aluminum. Chainring BCD: 110 Shimano Asymmetric. Defined Color: Black. Ring Position/TYPE: Chain Retaining Single Ring. Drivetrain Speeds: 10. Drivetrain Speeds: 11. Drivetrain Speeds: 12. Tooth Count: 38.