The Curtis 1221M-6701 Controller is a programmable DC series-wound motor speed controller for high-power electric vehicles. It supports 48V, 60V and 72V battery systems (maximum 80V), with peak rated current up to 550A. It is mainly used to regulate the speed and torque of DC series-wound motors. Applicable equipment includes industrial vehicles, material-handling vehicles, personnel carriers, golf carts and other electric vehicles.

The 1221M series is an upgraded programmable model derived from Curtis 1209, 1209B and 1221 series. Parameters can be configured, diagnosed and tested via the Curtis 1313-4331 handheld programmer or Curtis 1314 PC programming station to match the motor, throttle and operational requirements of different vehicles.