Pololu's compact brushed DC gearmotors pack a punch despite their petite size. This model is equipped with a 6V brushed DC motor, featuring long-lasting carbon brushes, and a 390.6:1 metal spur gearbox. The cylindrical gearmotor measures a mere 20mm in diameter, while the D-shaped output shaft is 4mm in diameter and protrudes 18mm from the faceplate of the gearbox.Key specifications of this gearmotor include a voltage of 6V, no-load performance of 36 RPM and 150 mA, and stall extrapolation of 16 kg⋅cm and 2.9 A. However, it's crucial to note that the gearbox torque limit is 5 kg-cm. Please refer to the detailed description for important product limitations.This Pololu gearmotor is ideal for a wide range of applications. Its compact size and powerful performance make it perfect for use in robotics, automation systems, and other small-scale mechanical projects. The long-life carbon brushes ensure longevity and reliability, reducing the need for frequent replacements and maintenance.The unique 390.6:1 metal spur gearbox offers high torque output and efficiency. This, combined with the gearmotor's small size, allows for optimal performance in compact spaces. The D-shaped output shaft is designed for secure coupling, ensuring steady and consistent power transmission.In summary, Pololu's 391:1 Metal Gearmotor is a robust, compact, and efficient solution for your various mechanical needs. Its unique features and high performance make it a reliable choice for a range of applications.