The High Power Gearbox is an excellent drive motor, using a good balance of speed and torque for maximum effectiveness.

Dimensions: 60 x 28 x 41mm (2.36 x 1.10 x 1.61in)
Shaft length: 80mm (3.15in)
Weight: 57 grams (1.9 oz.)
Motor Kv: 3475rpm/V
Stall current: 1.0A @ 3V
Gear ratios: 41.7:1 and 64.8:1
RPM: 250 and 160 @3V
Torque: 0.67kg-cm (9.30oz-in) and 1.04kg-cm (14.44oz-in) @ 3V

Can be run safely up to 8.4V
Select between two output shaft heights
Gearbox accepts 140 or 260 type motors
Mounts are built right into the gearbox.
Several types of crank arms are included for extra flexibility in design.