This gearmotor is a miniature (0.94" x 0.39" x 0.47"), low-current brushed DC motor with 50:1 metal gearbox, similar to Sanyo"s popular 12 mm gearmotors. These units have a 0.365"-long, 3 mm-diameter D-shaped output shaft. This version also has a 4.5 x 1 mm extended motor shaft.Key specs at 6 V: 250 RPM and 40 mA free-run, 7 oz-in (0.5 kg-cm) and 0.36 A stall.