e*thirteen Helix Race Alloy e*spec Crank Arm Set - BOSCH Gen4-Brose S Mag-TQ HPR50, 26.5mm Offset, 160mm, with Self Extractor, SilverA high performance, weight optimized alternative to carbon fiber, for riders who prefer alloy cranks. These 24mm ISIS interface cranks are engineered for compatibility with Bosch Gen 4, Brose S Mag, TQ HPR 50, Fazua, Yamaha, Maxon, and Specialized Brose motor systems. They come in short lengths starting at 155mm for improved pedal clearance and are tested to E Enduro standards. Product Specifics Color: Silver Crank Length (mm): 160 Pedal Spindle: 9