This voltage regulator is a good solution to the over-current problem caused by the small resistance while electric wire core is in cooling. Using the two-way high-power thyristor, the maximum current can get to 20A, easily adjust the output voltage at 0-220V. Widely used for appliances with power less than 4000W, such as electric furnace, water heater, lamps, small motor, and more. Features: The adjustable voltage range can be truly smooth and adjustable from 10V to 220V, making it more suitable for appliances needed low voltage to drive the heating wire. Dual Capacitance Design: Adopt amperometric capacitance + metal film capacitance to absorb surge and voltage spike, more efficient and safer to use. Wide Application: Use to adjust the speed, brightness, voltage, temperature of various electronic devices, such as electric furnace, water heater, lamps, small motor, etc. Durable Performance: Using high quality shell case, which is made of 1.5mm thickness aluminum and stainless steel, safe and convenient. Easy to use: Easily control voltage, speed, temperature and more via the adjustable rotary knob. Specifications: Color: Silver Material: Aluminum + Stainless Steel Input Voltage: AC 220V Voltage Regulation: AC 10-220V Power: Max. 4000W Efficiency: >90% Size: Approx. 85 x 55 x 38mm / 3.3 x 2.2 x 1.5in Package Weight: 127g Package List: 1 x Voltage Regulator Note: 1. The loaded power cannot exceed the specified maximum power, otherwise it will burn the module and electrical appliance. 2. Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.1、The adjustable voltage range can be truly smooth and adjustable from 10V to 220V, making it more suitable for appliances needed low voltage to drive the heating wire. 2、Dual Capacitance Design: Adopt amperometric capacitance + metal film capacitance to absorb surge and voltage spike, more efficient and safer to use. 3、Wide Application: Use to adjust the speed, brightness, voltage, temperature of various electronic devices, such as electric furnace, water heater, lamps, small motor, etc. 4、Durable Performance: Using high quality shell case, which is made of 1.5mm thickness aluminum and stainless steel, safe and convenient. 5、Easy to use: Easily control voltage, speed, temperature and more via the adjustable rotary knob.