Specification: Product name: single phase AC fan speed regulator Coating material: galvanized iron coating Model: 4000 W Wire length: 85 CM Input voltage: AC220V Product size: 114*100*80mm Rated current: 9A (limit current 18A) Product weight: 430g Voltage stepless (voltmeter does not work when voltage is lower than 10V) Voltage regulation range: ACO-220V stepless voltage regulation (with load) step down to 0V, boost 10V for rated power regulation: tungsten lamp 4000W, heating 3000W, power tools 2000W fan 1500W. Short-circuit overvoltage protection function SCR Model: STMicroelectronics BTA41-600B/800B Product Features: Zero hysteresis, zero delay, with peak voltage absorption circuit to effectively protect high power thyristor, surge protection, peak protection, absorption RC Precautions and instructions for use 1. The output voltage measured when the machine is empty is virtual voltage, and the correct output voltage must be measured at load greater than 20 W. 2. The above 4000W refers to the limit power when working with resistance load. The inductive load is 1/3 of the resistance load. Resistance load refers to tungsten lamps, heating wires, etc., and the inductive load refers to series driven motors, etc. Electronic products with printed circuit boards are not suitable for use. 3. The metal housing of this product must be securely grounded. Package contains: 1 Voltage regulator Have a great time shopping!