The use of two-way high-power thyristor, because the current up to 40 amps, a good solution to the electric furnace wire in the case of cooling resistance is too small to cause over-current problems; can easily adjust the mains output voltage, at 0-100% (220 volts sub-100 level adjustment, non-linear) between the arbitrary adjustment for the use of electrical appliances. Such as: electric furnace, water heaters, heating, lighting dimming, small motor speed, electric iron thermostat.In order to achieve dimming, tempering, regulating the effect. Large electric appliances that can be used for electric power less than 2000 watts Due to the large power, the average home electric appliances or small factories are enough. (This regulator is equipped with two-way high-power thyristor, can be used without any additional components, very convenient and practical). Comes with heat sink, the buyer can get the hand can be used,Brand Note:Charge does not exceed the maximum power, otherwise it will burn the module and electrical appliances; Use the resistive load as much as possible; Reduce the capacitive and inductive load of much energy. (It is best to leave more than half of them). Name:Voltage Regulator+Power Regulator Maximum power: 4000 W (resistive load connected) Voltage regulation: AC 0-220V, starts from AC 10V Protection: anti-peak, surge, RC absorption (EOC) Stable and durable.Used in electric furnace, water heater, lamps, small motor, electric iron etc. How to Use: The input is connected with the AC 220V. Output wire is connected to the electric cooker or appliance motor. Turn the knob for speed, voltage, temperature control. Colour:As Shown Material:Metal + Plastic Package Contents: 4 x Voltage Regulator 4 x Power Regulator