2pcs 12V/24V DC Motor Speed Controller Universal, Knob Screw Electronic Stepless Speed Regulator Switch Versatile Application: This DC motor speed controller is designed for automotive use, effectively managing fan heaters, defrosters, and other automotive fans. It supports both 12V and 24V systems, with a maximum load of 120W at 12V and 240W at 24V. Advanced Construction: Features a built-in heat sink for improved heat dissipation, helping to extend the lifespan of the controller. The rotary knob allows for smooth, stepless speed adjustment, providing precise control for various applications. Hassle-Free Installation: Simple wiring connections – connect the red wire to the positive terminals of the power supply and motor, the blue wire to the negative terminal of the motor, and the black wire to the negative terminal of the power supply. Universal Usability: Suitable for a wide range of DC motor applications, including automotive fans and other DC-powered equipment. Ideal for both DIY projects and professional use. Color: Black Material: Plastic Package Contents: 2 x Electronic Stepless Speed Controller Note: The actual product may vary slightly in color due to lighting and display differences. Measurement error allowed is +/- 1-3 cm.