Pololu's compact brushed DC gearmotors pack a punch in a small package. This model features a 6V brushed DC motor with long-life carbon brushes and a 250:1 metal spur gearbox. The cylindrical gearmotor has a diameter of 20mm, while the D-shaped output shaft is 4mm in diameter and extends 18mm from the face plate of the gearbox. Key specifications of this gearmotor include:- Voltage: 6V- No-load performance: 57 RPM, 150 mA- Stall extrapolation: 12 kg⋅cm (equivalent to 170 oz⋅in), 2.9 AThis gearmotor is perfect for a variety of applications. Its small size makes it ideal for projects where space is limited, but power is still needed. The long-life carbon brushes ensure durability and longevity, while the 250:1 metal spur gearbox provides high torque output.The gearmotor's unique properties include its compact size, high power output, and durability. These features make it a reliable and efficient choice for your project. Please note that the gearbox torque limit is 5 kg-cm. It's crucial to consider this product's limitations to ensure it suits your specific needs and applications.