Digital encoder knob to adjust motor speed, higher precision and better consistency than ordinary potentiometer adjustment, no drift Motor soft start function, the current increases slowly when starting the motor, no inrush current, effectively protect the motor and prolong the life of the motor. Adopt two high voltage and low internal resistance MOS tubes, as well as the front-stage driver, better and more stable performance, support for high-voltage and high-power Product Parameter: Working voltage: DC9V~60V, input anti-reverse connection protection Rated current: 12A maximum current 20A Maximum power: 500W Working frequency: 1KHZ~99KHZ adjustable, 1KHZ step, default frequency 20KHZ, precision of about 1%. Duty cycle: 0-100%, 1% stepping Installation hole size: 39.3MM x 76.5MM Material: plastic colour: As shown Package Contents: 1 x regulator Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.