Features: PWM Motor Controller has its own soft start function. When starting the motor, the current increases slowly without inrush current, which effectively protects the motor and prolongs the service life of the motor. Achieve precise control over your motor speed with the DCMotor Controller, providing adjustable frequency settings for high performances. The soft start function of this motor controller ensures a gradual increase in current, protecting your motor and extending its service life. Designed for wide ranges of applications, this motor controller is suitable for professionals and DIY enthusiasts, offering versatile control option. Operating frequency: 1KHz ~ 99KHz adjustable, duty cycle: 0-100%, operating voltage: DC9V ~ 60V; Specifications: Material:ABS Color:Black Size:Approx.78x48x27mm/3.07x1.89x1.06in Working Voltage: Dc9v~60v, Input Anti-Reverse Connection Protect Rate Current: 12a Most Current 20a Most Power: 500w Working Frequency: 1khz~99khz Adjustable, 1khz Step, Default Frequency of 20khz, Accuracy of About 1% Duty Cycle: 0-100%, 1% Step Package Includes: 1xSpeed Controller note: Please allow 1-2cm errors due to manual measurement,please make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.