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 control of input power, enabling easy power on/off. Features a peak voltage absorption circuit for effective protection of the SCR, ensuring no delay or lag during operation. 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 and safe connections. Designed with user-friendly mounting holes for flat placement or wall hanging. Operates silently, energy-efficient, with stable anti-noise performance and wide application range. Suitable for use with electric stoves, water heaters, heat lamps, small motors, soldering irons, and other resistive or inductive loads. Note: Output voltage readings taken without a load are inaccurate. A minimum 20W load is required for correct voltage measurement. Input and output are AC only, not DC. The 4000W rating applies to resistive loads only. 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 Max Power: 4000W Voltage Adjustment Range: 0–220V Rated Current: 9A Max Current: 18A Unit Size: 115 x 100 x 83mm (4.53 x 3.94 x 3.27in) Unit Weight: 459g (1.01lb) Package Size: 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