This is a high-quality, high-power SCR voltage regulator with stepless control, designed to adjust speed, temperature, voltage, and light. 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 an independent switch for easy control of input power and power cutoff. Features a peak voltage absorption circuit for effective protection of the SCR with no delay or lag. 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 industrial-grade sockets with thickened copper contacts for reliable connection and safety. Designed with mounting holes for flexible installation on flat surfaces or hanging positions. Operates silently, energy-efficient, stable, and noise-resistant, suitable for a wide range of applications. Ideal for use with electric stoves, water heaters, heat lamps, small motors, soldering irons, and other resistive or inductive loads. Note: When measuring output voltage without load, the reading is a phantom voltage. A load of at least 20W is required for accurate measurement. Input and output are AC only, not DC. The rated 4000W capacity applies to resistive loads; inductive loads should not exceed one-third of the rated power. Use caution when connecting electronic devices or inductive loads such as motors. This unit has a metal case and must be properly grounded. Specifications: Name: SCR Voltage Regulator Model: NHT-4000W Material: Aluminum Color: Black Input Voltage: AC 220V Output Voltage: 0–220V Maximum Power: 4000W Voltage Adjustment Range: 0–220V Rated Current: 9A Maximum Current: 18A Unit Dimensions: 115 x 100 x 83mm (4.53 x 3.94 x 3.27in) Unit 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 Includes: 1 x SCR Voltage Regulator