This is the Planetary Gear Drive for use with 24mm-28mm ElectriFly Ammo Motors. / / FEATURES: Allows you to mount up to 685 watts of power in a slender, 28mm / diameter package / Planetary gears with 3 roller bearings and an output shaft supported / by 2 ball bearings / / INCLUDES: One Planetary Gear Drive / One 3mm ID Pinion Gear / One 3.175mm ID Pinion Gear / Four Washers / Four 3x6mm Button Head Screws / Instruction Sheet / / REQUIRES: Prop Adapter-Collet or Collet Cone Adapter / GPMQ4966 5mm to 5/16-24 Collet Prop Adapter / GPMQ4994 5mm to 5/16-24 Collet Cone Adapter / / SPECS: Gear Ratio: 4.3:1 / Pinion Gear Teeth: 14T / Ring Gear Teeth: 46T / Weight: 53g (1.9oz) / Input Shaft Diameter(motor shaft diameter): 3mm(0.12"),3.175mm(0.13") / Output Shaft Diameter (gearbox output): 5mm (0.20") / / COMMENTS: For mounting inside cowled applications, order the Aluminum Medium / Brushless Motor Mount-GPMG1255.