KMC Sprocket for SHIMANO WIDE 17T E-Bike Hardened chrome-molybdenum steel For Shimano Maximum performance that saves battery life Perfectly matched to KMC chains Recommended chain: e101EPT Item no.: BSRS5817 Size: 1/2 X 1/8 (single speed only) Color: black 10,000 km+: Lasts. And lasts. And lasts. The 10,000 km+ drivetrain is the solution for frequent drivers. Pairing our e101 EPT/eCargo1 chain with one of our 3mm-wide sprockets and chainrings guarantees 10,000 km+.