Voltage and Current Tester: When overvoltage, undervoltage or overcurrent occurs in the circuit, the voltage protector can immediately cut off the power supply to protect the electrical equipment from damage. And automatically resets when the line voltage returns to normal. Circuit Protection: The surge protector is suitable for monitoring three-phase four-wire power systems or electrical equipment, providing protection for overvoltage, undervoltage, overcurrent, three-phase asymmetry and phase sequence errors in electrical equipment, thereby protecting your electrical safety. Real-time monitoring: With LCD display, overvoltage and overcurrent dual display, the voltage status is clear at a glance, and the real-time display is clearer. Easy to use The surge protector is installed on the DIN35mm universal standard guide rail, no screws are required, easy to install, compact, convenient and practical. Safe to use Built-in magnetic latching relay, which will not burn out due to of high current impact. The shell is made of high quality PC material, flame retardant and high temperature resistant, with insulation protection.