The automatic recovery over voltage and under voltage protective device complies with modular design standards. the circuit boards of products adopt good quality electronic components with reliable performance. When the power situation is unstable, It's protective function will be automatically activated. once the voltage exceeds the limited range of products, it will automatically cut off so as to protect the safety of electrical equipments and persons. The device will re-supply after 1 minute, when the power returns to normal.The green indicator displays, when the power is in normal supply.The red indicator displays, when the power is over voltage or under voltage.