1、High quality, input connection AC 220V, output connected to electric furnace wire or motor equipment, then rotate the knob for speed, voltage and temperature control. 2、Generally used in electric furnaces, water heaters, lamps, small motors, electric irons, etc. 3、The insurance cover can make sure the durability of the product. 4、This AC voltage regulator has a simple structure and easy operation. 5、Professional design of AC voltage regulator, stable performance, rest assured to use. Description: Working voltage: AC 220V Regulation voltage: AC 10-220V Max power: 4000W (resistive load) Efficiency: 90% Dimensions: 85 x 55 x 38MM Note: You must connect to the load before the regulator. SCR is mainly used for resistive loads (incandescent electric wire, etc.), most of the single-phase AC motor can, but can not guarantee, other types of loads buyer to confirm their own. Fuse is not a panacea, there is reaction time, if the current is too large, in addition to burn the fuse, the module may also be burned. Attention to fitting plastic cover due to the installation of the housing, can not be completely open, screwdriver to tighten the side with the point, the other to be careful when opened, excessive force easily snapping the lid, express transportation may also crushed for wearing parts, but It does not affect the module. Package included: 1 x 4000W AC220V SCR silicon controlled electronic volt regulator 1 x 4000W AC220V SCR silicon controlled electronic volt regulator