Wolf Tooth 120 BCD Chainring - 36t 120 BCD 4-Bolt Drop-Stop B BlackDesigned as a direct replacement for cranks or 4 bolt spider utilizing a 120 BCD. These rings will allow you to convert your 120 BCD crankset like the SRAM XX and others to a 1x application. They feature Wolf Tooth's proprietary mud clearing Drop Stop tooth profile design. NOT Compatible with Full Speed Ahead (FSA) 4 bolt cranksets. Features Wolf Tooth's Drop Stop tooth design for maximum chain retention Drop Stop chainrings are designed for use with