The Wolf Tooth Direct Mount Chainrings for Bosch E-Bike Motors are compatible with all Boost and Super Boost bikes that use the Bosch Gen 4 E-Bike Motor.This continues the Wolf Tooth product line of Drop-Stop chainrings for e-bike motors.Direct Mount Chainrings for Bosch E-Bike Motors are machined with 7075-T6 aluminum at Wolf Tooth in Minnesota, USA.Compatibility.-Chainring is compatible with most bikes that use the Bosch Gen 4 e-bike motor.Not compatible with Pivot bikes using Superboost chainline.-55mm chainline.-Use Drop-Stop B for all 9, 10, and 11spd chains or 12spd SRAM Eagle, SRAM Flattop Road or Transmission (T-Type), Connex or Wippermann chains.Tech Specs.-Weights:32t.-98g 34t.-105g .Material: 7075-T6 aluminum.-Color:Black.-Made in the USA.