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 a separate switch for independent control of input power, enabling easy power cutoff. 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 mounting holes for flexible installation options. 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 without a load are not accurate. A minimum 20W load is required for correct voltage measurement. Input and output are AC only. The 4000W rating applies to resistive loads; inductive loads should not exceed one-third of rated capacity. Examples of resistive loads include heating elements and incandescent lamps. Use caution when connecting electronic devices. The 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