This is the Robinson Gen3 Slipper Unit for the HPI Racing Blitz. FEATURES: Steel spur gear Aluminum slipper plate Heavy-duty slipper pad Ball bearing supported spur gear INCLUDES: One spur gear, one slipper plate, one slipper pad, one ball bearing instructions and decals REQUIRES: Installation following the included instructions SPECS: Spur Gear Tooth Count: 88 Pitch: 48 COMMENTS: Robinson recommends using their hardended pinions RRPC1416 - RRPC1428 when using this set up. ajw 11-03-10