The R3 Single Speed Transmission comes with a tough cast metal case and gears to allow for more abuse along with a Delrin Spur with Slipper Clutch. It also features a sturdy billet aluminum motor mount for durability. Specifications Clockable Motor Mounting (10 different positions) CNC Aluminum Motor Mount Single Speed Slipper Clutch Design Weight: 303g Colour:A silver Material:Metal Package Contents: 1 * R3 Single Speed Transmission 1 * Mounting Accessories Set Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.