104 BCD is the most common bolt pattern on double and triple cranksets and happens to be the first product ever made by Wolf Tooth Components. This chainring started it all for us. The Drop-Stop tooth desing is the best performing and longest lasting wide/narrow chainrings on the market. - Fits any 104 BCD crankset - Drop-Stop technology. On Wolf Tooth's patented wide/narrow chainring, the wide side of the tooth has maximum contact on the drive side which spreads the load and improves chainring life. The narrow side allows clearance for mud and debris which reduces friction. - Drop-Stop B is designed with narrower teeth to accomodate large rollers on SRAM Flattop chians. Works with all 9 speed, 10 speed and 11 speed chains. Also works with 12 speed Connex, Wipperman, Campagnolo, SRAM Eagle, SRAM Road (Flattop)and SRAM Transmission (Flattop) chains - Alternating wide/narrow tooth pattern prevents chain derailment Compatibility - Fits any 104 BCD crankset. - Designed to meet the requirements for E-bike use. - All sizes of 104 BCD chainrings are compatible with QUARQ power meters. - Drivetrains: 1x9. 1x10, 1x11, 1x12 can all be used. If using a 9 speed drivetrain, use a 10 speed chain. It fits tighter for better chain retention.