Progressive Industries' Hardwired Electrical Management System (EMS) provides full RV surge and electrical protection against all adverse power conditions. Whenever electrical power falls below 104 volts or rises above 132 volts, the EMS automatically shuts down power to the RV. Once the electrical power rises above 104-volts, or below the 132-volt level, the time delay indicator flashes for the preset time and then automatically restores power to the RV. Features include: Built-in digital readout, built-in surge fault indication, amperage meter, voltage meter, frequency meter, integrated digital readout, 3-mode surge protection, and reverse polarity protection, open neutral/open ground protection, lost/open neutral protection and AC frequency protection. Factory setting 15 seconds but can be adjusted to a 2 minute 16 seconds (136 seconds) delay for A/C Protection. Frequency Protection (Low | Marinco Surge Protector with Voltage Protection, Hardwired 50-amp