Note: These are cheap, high-performance motors, so they have notably low lifetimes, especially at higher voltages. Think of them as fireworks.
Overview
This brushed DC motor is great for applications where you want a lot of power in a small package. We generally recommend running it between 1.5V and 3V, but it can operate at higher voltages to provide more power in exchange for longevity of the motor. For example, at 6V, the speed and torque are approximately twice what they are at 3V, but it will also draw twice as much current, and it will have a significantly shorter life. In our tests, the motor was able to run continuously at 6V without any load for approximately five hours before failure.
This motor is a generic alternative to the Solarbotics RM2 motor, offering nearly identical performance in the same form factor. It can be used to provide more speed and torque to gearmotors driven by lower-power 130-size motors, such as our larger Pololu plastic gearmotors (228:1 offset, 120:1 offset, 200:1 90-degree, and 120:1 90-degree) and Solarbotics plastic gearmotors (GM2, GM3, GM8, and GM9). Some people have even been using motors like this to enhance their flywheel NERF guns!
4 June 2019 Update: We have corrected the published no-load speed of this product to be 20kRPM. (Our previously published speed of 17kRPM is actually the speed at a load of 10gf*cm.) The product itself has not changed.