Modular Design: Overvoltage and undervoltage protectors with automatic reset function comply with modular design standards. Reliable Material: The overvoltage and undervoltage protector is made of high-quality electronic components for reliable performance. AC rated voltage: 230V 50Hz, maximum transmission current 40A Surge protection: The protection function is automatically activated when the power supply is unstable. When the voltage exceeds the limited range of the product, the product will automatically cut off to protect the safety of electrical equipment and personnel. Indicator light: When the power supply returns to normal, the adjustable voltage and current protector will restart within 1 minute. The green light indicates that the power supply is working normally. The red light indicates overvoltage or undervoltage. Tip: When you plug in the product for the first time, wait about 1 minute. Only when the red light goes out can the product work normally.