This is the Great Planes ElectriFly Ammo 28mm Gear Drive.
This bolts directly to the ElectriFly Brushless Motor Mount (GPMG1255).
FEATURES: For 28mm Ammo Motors and most other 28mm In-runner motors
High-precision spur and pinion gear for quiet operation
Dual ball bearing-supported output shaft
INCLUDES: One gear drive
All assembly hardware
Two different pinion gears 11T and 16T
40T and 50T spur gear
Collet style prop adapter
REQUIRES: Attaching to the motor mount
SPECS: Length: 2.4" (60.9mm) approx.
Width: 1.4" (35.5mm) approx.
Motor output shaft dimension: 3.175mm
Prop adapter shaft dimension: 5mm to 5/16-24
Gear ratios included: 2.5:1, 3.1:1, 3.6:1, 4.5:1
2.1:1 with 16T pinion and 40T spur
3.1:1 with 16T pinion and 50T spur
3.6:1 WITH 11T pinion and 40T spur
4.5:1 with 11T pinion and 50T spur
Weight: 1.2oz (34g)
update JAW 1/19/11