Light commercial or residential surge protection! This affordable surge protector is suitable for homes with main breaker panel capacities up to 400 amps. Designed for 120/240 volt single or split-phase service. Install this unit next to your breaker panel closest to where the electrical service enters your home. This product stops transient surges before the event can get into your home and cause damage. It can be installed indoors or outdoors. It has been tested to the latest requirements of NEC Section 285 and can be installed in any location with a fault current rating of 25 KAIC or less. -Hardwired to your breaker panel -Protects Incoming Power -Can be installed indoors or outdoors -Green LEDs lit when working Properly -Red LEDs indicate diminished protection, replace unit immediately