The RaceFace Aeffect R eMTB cranks bring the burly purpose-driven design of Aeffect R to the Bosch drive system for seamless motor integration.Optimized for use with Bosch Gen 4 Performance Line CX drive systemsCompatible but not optimized for use with Bosch Gen 2 drive systemsConstructed of 7050 Aluminum TECH SPECS table{border-collapse:collapse;width:100%;} td{text-align:left;padding:8px;font-weight:350;} tr:nth-child(even){background-color:#f2f2f2} th{background-color:#eb212e;color:white;text-align:left;padding:8px;} .desc .specs-heading{font-size:24px;font-weight:600;padding-top:35px;border-top:3px solid #f0f0f0;display:inline-block;border-bottom:4px solid #eb212e;width:142px;margin:0;} Color Black Pedal Spindle 9/16" Spindle Interface Type ISIS Designed for ebike Yes Defined Color Black Size 160Mm