Features: 100% brand new and high quality Universal: 12V or 24V, supporting high power. Wiring: The red wire is connected to the power supply and the positive pole of the motor, the blue wire is connected to the negative pole of the motor, and the black wire is connected to the negative pole of the power supply. Heat dissipation: This electronic stepless speed controller is an upgraded fan heater controller with a heat sink, which will ensure better heat dissipation. Wide range of applications: suitable for 12-24V DC electrical appliances. Adjust motor speed, car heater control, defrost, fan speed control, etc. Easy to use: The motor speed control is convenient, and the wiring is simple. It is an excellent substitute for power failure. Extra-long knob screws to meet installation needs. Package Includes: 1x Controller Switch Specifications: Material: Metal + Plastic Model: Infinite Switch 10A/ Infinite Switch 20A/ Infinite Switch with Heat Sink/ Infinite Switch Without Heat Sink Size: Approx. 8x3.2x3.5cm/3.14x1.25x1.37inch Voltage: DC 12V-24V Rated Power: 12V/200W ; 24V/400A note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.