High Quality: Use high performance SCR as internal chip. Thickening metal shell, high temperature resistant and durable in use. Leistung Perfect Performance: Stepless voltage adjustment with rotary knob, zero hysteresis, zero delay, fast response. The AC voltage regulator cover is equipped with a universal multi-purpose socket and a current display. Effectively protect high-performance thyristors against overvoltage and voltage limits with multiple protection Note 1: The 4000W mentioned above refers to the maximum power when working under resistive loads . Power under inductive load is 1/3 of resistive load. The resistive load concerns Wolframlampt Diew. on line excitation motor and more. Electronic products with 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. Product Description Specification: Model: Input Voltage BTA-4000W Power: AC 220V Plug type: EU plug Output voltage: 0-220V continuously adjustable (voltmeter does not work not if the output voltage is less than 5V) 2000 ohmic spirits Lemmer Lester W up to 3000W) Rated current: 9A Current limit: 18A Package weight: approx. 507g Package List: 1 x Speed Controller 220V