Wolf Tooth Direct Mount Chainrings for Bosch Gen 4 E-Bike Motors are compatible with all Boost and Super Boost bikes that use the Bosch Gen 4 Motor. This brings a lightweight chainring with patented Drop-Stop technology to e-bike chainrings for the first time. Direct Mount Chainrings for Bosch Gen 4 E-Bike Motors are machined with 7075-T6 aluminum at Wolf Tooth in Minnesota, USA.Drop-Stop ST for use with Shimano 12-speed Hyperglide+ and 12spd KMC chainsItem SpecificationsColorBlackDefined ColorBlackDesigned for ebikeYesTooth Count32 Wolf Tooth Bosch Gen 4 Direct Mount Ebike Chainring eBike Chainrings and Sprockets UPC: 810006808544