A device that can automatically disconnect when the overvoltage and undervoltage in the circuit exceed the specified value, and can automatically detect the circuit voltage. It can automatically close when the voltage in the circuit returns to normal. Mainly used for household and shopping mall power distribution lines (singlephase AC230V, threephase four wire AC415V). Features: Real time protections of household electricity safety. The corresponding current size can be customized based on the electric field. If the electricity used in the dormitory is 5A, a 5A current limiting controller can be customized. If it exceeds 5A, the power will be automatically cut off. After the electrical equipment is unplugged, the current will return to within 5A, and it can also be automatically restored. Small size, simple wiring method, and very easy to use. Dual dispaly, clear and convenient to view the current and voltage. Equipped with a work indicator light, the electrical status is clear. Specifications: Main color: white Rated voltage: 220VAC, 50/60HZ Rated operating current: 63A Operating voltage range: 80-400VAC Electric current(A)setting range: 1-63A Overvoltage(U)setting range: 230-300V Undervoltage(U)setting range: 120-210V Delay: 0.5s Reset delay: 1-600s Rated insulation voltage: 400V Item size: 85 * 66 * 37mm / 3.3 * 2.6 * 1.5in Item weight: 153g / 5.4ounce Package size: 90 * 70 * 40mm / 3.5 * 2.8 * 1.6in Package weight: 168g / 5.9ounce Packing List: 1 * Voltage Protector 1 * User Manual