Specification: Name: SCR Voltage Regulator Size: 100*84*53mm/3.94*3.31*2.08in Weight: 0.418 Kg Material: Iron Color: Gray Input Voltage: AC 220 V Output Voltage: 0-220 V Adjustable (Voltmeter does not Work When The Output Voltage is Lower Than 5V) Maximum Power: 4000 W. (Adapt to 2000W-3000W Resistive Load) Voltage Regulation Range: 0-220 V Steplessly Adjustable (Under Load Conditions) Step-Down to 0V, Step-Up from 10V Rated Current: 9A Maximum Current: 18A Note: 1.The Load must be Connected Before Adjusting The Voltage (Test Voltage) 2. When The Machine is Empty, The Output Voltage is Measured as a Virtual Voltage. It must be Connected to a Load of 20 Watts or More to Measure The Correct Output Voltage. 3.The 4000W Mentioned Above Refers to The Limit Power When Working in a Resistive Load. The Inductive Load is 1/3 of The Resistive Load. Resistive Load Refers to Tungsten Filament Lamps, Heating Wires, Etc., Inductive Load Refers to Series-Excited Motors, Etc., and Circuit Board Electronic Products should be Used With Caution. 4. When Inputting AC Power, The Output is Also AC Power, Not DC Power. 5. This Product is a Metal Shell and must be Safely Grounded Packing List: 1 * SCR Voltage Regulator 1* Manual