The controller adjusts the temperature of the heating plate based on pulsation. In position 1 it will pass little energy and pulse slowly. In position 6 the WPR pulses quickly and lets a lot of energy pass through. In position 7 the controller lets full power pass through without pulsing. The pulsation can be detected by the flashing LED indicator of the heating plate. This product is not waterproof; therefore, it should only be used in a dry state.