This is powerful wheelchair motor. They make great heavy-duty robot motors. 250W 80RPM motors with 17mm keyed shaft output. They are sold individually and have an encoder mounted on the back.
The HD2 tracked platform is a large, heavy duty tracked robot with the power to pull a truck and climb stairs. A wealth of internal space allows for batteries, controls and an optional computer. Customized version of item TP-200-001.