2366-POLOLU 75:1 Micro Metal Gearmotor MP 6V
This gearmotor is a miniature medium-power, 6 V brushed DC motor with a 75.81:1 metal gearbox. It has a cross section of 10 × 12 mm, and the D-shaped gearbox output shaft is 9 mm long and 3 mm in diameter.
Key specs at 6 V: 290 RPM and 40 mA with no load, 17 oz-in (1.2 kg-cm) and 0.7 A at stall.