[Wide Voltage]: Wide voltage input 7-70V, maximum output current 30A (Please refer to the recommended power range for actual use current. It is recommended that 12V within 250W, 24V within 350W, 48V within 450W, and 60V within 500W. ) [Speed Control Knob]: The knob has a switch function, which can control the motor speed from 0 percent to 100 percent . Adjustable potentiometer flexible cable can be separated, the cable length is 15CM. [30A Fuse]: This set contains a 30A fuse to prevent shorting of the motor interface. Double protection of your Motor and Motor Speed Controller. [Note 1]: The power of the input power supply must be greater than 1.5 times the rated power of the motor to make the motor work (note: the input voltage and the rated voltage of the motor must be consistent). [Note 2]: If there is a forward-reverse circuit regulator on the children's car, please be sure to connect the speed controller between the power supply and the forward -reverse circuit regulator of the children's car. Otherwise, the speed controller may be damaged. Precautions: The module is a DC motor speed controller and cannot be connected to AC power. The power of the input power supply must be greater than 1.5 times the rated power of the motor to make the motor work (note: the input voltage and the rated voltage of the motor must be consistent). Modification for Children's Car If the product is used in the modification of children's car, the output end of the speed controller can be connected with a Forward and Reverse Switch to realize the function of forward and reverse control. If there is a forward and reverse circuit regulator on the children's car, please be sure to connect the speed controller in front of the forward and reverse circuit regulator (In other words: between the power supply and the forward and reverse circuit regulator) of the children's car. Otherwise, the speed controller may be damaged. Specification: DC Motor Speed Controller Applicable voltage range: DC 7-70V Drive current: max. 30A (Please refer to the following "Control power (recommended)" for actual use current) Control power (recommended): 12V: within 250W 24V: within 350W 48V: within 450W 60V: within 500W Duty cycle adjustable range: about 1 percent -100 percent PWM frequency: 12KHz Fuse: Current: 30A max Wire diameter: 2.5mm2 or 0.4cm diameter or 12AWG Length of wire: 26cm (total length including 30cm) Material:ABS colour:As Shown Package Contents: 1 x DC Motor Speed Controller Only the above package content, other products are not included. Note: Light 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.