2825-POLOLU 70:1 150RPM Metal Gearmotor 37Dx70L mm with 64 CPR Encoder
This gearmotor is a powerful 12V brushed DC motor with a 70:1 metal gearbox and an integrated quadrature encoder that provides a resolution of 64 counts per revolution of the motor shaft, which corresponds to 4480 counts per revolution of the gearbox’s output shaft. These units have a 0.61"-long, 6 mm-diameter D-shaped output shaft.
Key specs at 12 V: 150 RPM and 300 mA free-run, 200 oz-in (14 kg-cm) and 5 A stall.