Feature: 1. Easy for Control: Supports stepless adjustment, the motor controller ensures smooth and stable control on the overall speed and operation. 2. Input and Output: Designed for AC input and AC 0~ output, the AC motor speed regulator ensures high working efficiency with safety. 3. Wide Application: Ideal for adjusting speed, voltage, temperature, lighting and more, can be used on fan, tungsten bulb, electric furnace, angle grinder, marble machine, blower and morel. 4. The Working Tips: Cannot be used for electrical appliances with circuit boards and capacitive electronic components, such as microwave ovens, rice cooker, water pumps, washing machines, LED energy saving lights, etc. 5. Quick to Install: Light in weight and compact in size as well, the variable motor speed controller is very convenient to install in minutes. Specification: Item Type: Motor Speed Controller Model: WF-850. Package List: 1 x Motor Speed Controller Note: 1. The output voltage measured under mains power is an analog voltage, and a load of over 20W must be connected to measure the correct output voltage. 2. The product inputs AC voltage and outputs AC power. The input voltage is equivalent to the output voltage, and cannot be used as a boost product. 3. 4000W is the maximum power of the module under resistive load, with inductive load accounting for 1/3 of the resistive load. Resistive load refers to tungsten filament lamps, heating wires, etc., and inductive load refers to series excited motors, etc. Be cautious when using circuit board electronic products.4. Resistive load refers to the temperature and light regulation effect of tungsten filament lamps and heating wires, while inductive load refers to the voltage and speed regulation effect of motor fans.