This is a pololu 78:1 Metal Gearmotor 20DX43LMM 6V Dual, which is a type of small, direct current (DC) motor. It has a reduction ratio of 78:1 and a voltage rating of 6V, so it has a moderate torque output. The 20DX43LMM has long mounting tabs, which makes it suitable for use with a wide variety of drive styles, including worm gears and planetary gears. Additionally, its size, weight, and power make it ideal for embedded projects or small robots.