Save a little cash with this Box Three cassette paired to the durable Box Two derailleur, shifter and chainIncludes Box Three cassette, Box Two rear derailleur, Box Two shifter and chainWide range 9 speed single-shift group for use with e-bikesSingle Shift per swing for E-Bike safe shiftingDerailleur features Box`s Tri-Pack Limited Slip ClutchGlass fiber / nylon composite, steel and aluminum constructionMatte black finishBlackUPC/EAN/GTIN: 785249137723