2 Pcs Universal DC Motor Speed Controller for 12V/24V Systems, Car Truck Fan Heater Speed Control Switch

["This is a Universal DC Motor Speed Controller, designed to adjust the speed of fans, heaters, or defrosters in vehicles or DIY projects.","Specifications: Operates on 12V or 24V DC power and can handle up to 10 amps of thermal current.","Rated Power: Supports loads up to 120W at 12V, or 240W at 24V.","Features: Features an external aluminum heat sink for improved heat dissipation and a knob for smooth, stepless speed regulation.","Wiring: The red wire connects to the positive power supply and motor, the blue wire connects to the negative motor pole, and the black wire connects to the negative power supply."]