Designed 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. Made from 7075 Aluminum for long life Features Wolf Tooth&';s Drop-Stop tooth design for maximum chain retention Optimized for use with 10, 11, and 12 speed chains Not compatible with 9 speed chains 49mm chain-line for 135/142mm (non-boost) rear hub spacing