[Wide Voltage]: Wide voltage input 7-70V, maximum output current 30A (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 that can control the motor speed from 0% to 100%. Adjustable potentiometer flexible cable can be separated, cable length is 15CM. [30A Fuse]: This set includes a 30A fuse to prevent short-circuiting of the motor interface. Double protection of your motor and motor speed controller. [Note 1]: The input power supply's power must be 1.5 times the motor's rated power to make the motor work (Note: the input voltage and the motor's rated voltage must be consistent). [Note 2]: If there is a forward-reverse circuit controller on the children's car, be sure to connect the speed controller between the power supply and the forward-reverse circuit controller 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 input power supply's power must be 1.5 times the motor's rated power to make the motor work (Note: the input voltage and the motor's rated voltage must be consistent). Modification for Children's Car If the product is used for modifying a children's car, the speed controller's output end can be connected to a forward and reverse switch to realize the forward and reverse control function. If there is a forward-reverse circuit controller on the children's car, be sure to connect the speed controller in front of the forward and reverse circuit controller (In other words: between the power supply and the forward-reverse circuit controller) 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 (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 Adjustable Working Range: Approx. 1% -100% PWM Frequency: 12KHz Fuse: Current: 30A Max Wire Diameter: 2.5mm2 / 0.4cm diameter / 12AWG Wire Length: 26cm (Total length including seat 30cm) Material: ABS Color: As Shown Package Contents: 1 x DC Motor Speed Controller Only the above package content, others are not included. Note: Light and different displays may cause the color of the item in the picture to differ slightly from the real item. The allowed measurement error is +/- 1-3cm.