This is a high-quality, high-power SCR voltage regulator with stepless control, designed to adjust speed, temperature, voltage, and lighting. It features a high-temperature resistant FR-4 circuit board, imported SCR chip, full aluminum heat sink, precision resistors, and high-voltage capacitor. Equipped with a separate switch for independent power input control, allowing easy power activation and disconnection. Features a peak voltage absorption circuit for immediate response with no delay, providing effective protection for the high-power SCR. Offers surge and spike protection with RC absorption and multiple safety protections. The flame-retardant insulated enclosure is heat-resistant, rustproof, pressure-resistant, and durable. Includes multi-functional industrial sockets with thickened copper contacts for reliable and safe connections. Designed with mounting holes for flexible installation options, whether placed flat or hung. Operates silently, energy-efficient, with stable anti-noise performance and wide application range. Suitable for use with electrical devices such as electric stoves, water heaters, heat lamps, small motors, soldering irons, and more.Note: When measuring output voltage without a load, the reading is a phantom voltage. A load of at least 20W is required for accurate voltage measurement. Input and output are AC voltage only, not DC. The 4000W rating applies to resistive loads. Inductive loads should not exceed one-third of the rated power. Resistive loads include heating elements and incandescent lamps; inductive loads include motors. Use caution when connecting sensitive electronic devices. This product has a metal casing and must be properly grounded for safety.Specifications: Name: SCR Voltage Regulator Model: NHT-4000W Material: Aluminum Color: Black Input Voltage: AC 220V Output Voltage: 0–220V Max Power: 4000W Voltage Adjustment Range: 0–220V Rated Current: 9A Max Current: 18A Main Unit Dimensions: 115 x 100 x 83mm (4.53 x 3.94 x 3.27in) Item Weight: 459g (1.01lb) Package Dimensions: 180 x 100 x 115mm (7.09 x 3.94 x 4.53in) Package Weight: 522g (1.15lb) Package List: 1 x SCR Voltage Regulator