: Use high-performance SCR as the internal chip. Thickening metal shell, high temperature resistant and durable in use.Perfect Performance: Stepless voltage adjustment with rotary knob, zero hysteresis, zero delay, fast response.The cover of the AC voltage regulator is equipped with a universal multi-purpose socket and current display. Effectively protect high-performance thyristors from overvoltage and voltage limits with multiple protection.Note 1: The 4000W mentioned above refers to the maximum power when working under ohmic loads. The power under inductive load is 1/3 of the ohmic load. The ohmic load refers to Wolframlampt Diew. on the line excitation motor and more. Electronic products with printed circuit boards should be used with caution. Note 2: The measured output voltage is a virtual voltage if there is no load. It must be connected to a load of 20W or more to measure the correct output voltage. The output is a Wehtselstrom metal shell and must be safely grounded.