These tiny gearmotors are available in a range of gear ratios. All of the micro metal gearmotors have the same physical dimensions, so one version can be easily swapped for another if your design requirements change.
This gearmotor is a miniature (0.94" x 0.39" x 0.47"), high-power brushed DC motor with 100:1 metal gearbox, similar to Sanyo’s popular 12 mm gearmotors. These units have a 0.365"-long, 3 mm-diameter D-shaped output shaft.
The Sabertooth 2X25 is one of the most versatile, efficient and easy to use dual motor drivers on the market. It is suitable for medium powered robots - up to 30lbs in combat or 100lbs for general purpose robotics. Made by Dimension Engineering.