S06P 250Watts Torque Simulation Square Wave Controller for 24Volts and 36Volts battery pack E-Bike System. It unitilizes the huge database from pedaling movement to imitates real torque sensor. Many customers tried this kind of controllers, all said "It is more comfortable than real torque." Of course, there is no real torque sensor, so it it more reliable. As the saying goes, less parts, more reliable.1. For 24V and 36V batteries;2. It fits all S series LCD and LED meters.3. For 250Watts sensorless motors.4. Dimension: 31x51x86mmNote: This kind of controllers are not as same as the other commom controllers. It is the torque simulation controller. So when you change the level of the PAS by LCD or LED panel, the speed will not change. They are in same speed. But the torque is different. In other word, the output of controller power is different.