Special design with 1.6 thick FR - 4 high temperature resistant circuit board. It is safety and reliable to cope with current. Double capacity design: Safety capacitor and Metal film capacitor to more effective.More efficiency and more safety. 1.5 thick aluminum and stainless steel case, more suitable for family temperature control or speed control and industrial enterprises to .Beautiful and easy, safe, convenient, high quality products. It will not rust after long time using. Mainly fit for the resistive loads, eg. lights. It also works with the single phase brushed motor which the max can NOT be over the 1/3 of 40000W. Some Application: Electric furnace, water heater, lamps, small motor, electric iron etc.Attention: Load does not exceed the maximum , otherwise it will burn module and electrical appliances; the resistive load as as possible; reduce inductive and capacitive load greatly. ( it is to leave more than half of ) Voltage range:10V-220Vmaximum Net Weight: 41.8g Radiator fin size: 48 x 35 x 30mm Working Voltage: AC 220V Maximum : 4000W (connected resistive load) Protection: Anti-, Surge, RC absorption (EOC) color:As shown Material:Plastic + Metal Package Contents: 1 x 4000w governor(with fan) Only the above package content, other products are not included. Note: Light reflection and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.