BOX TWO/THREE PRIME 9 X-WIDE/SINGLE SHIFT E-BIKESave a little cash with this Box Three cassette paired to the durable Box Two derailleur, shifter and chain Includes Box Three cassette, Box Two rear derailleur, Box Two shifter and chain Wide range 9 speed single shift group for use with e bikes Single Shift per swing for E Bike safe shifting Derailleur features Box`s Tri Pack Limited Slip Clutch Glass fiber nylon composite, steel and aluminum construction Matte black finish