FIRST DEFENSE 100-series hardwired unit is rated to 150,000 Amp Total Peak Surge Current Rating, approximately 2.5X the average amps in a lightning strike. This device offers All Mode Protection that covers every electrical path. For a 120-Volt/240-Volt (50 Amp circuit) this device protects the L-N. and L-G. This unit also includes EMI/RFI filtering in the standard configuration. Highly recommended for those who use electronics utilizing microprocessors, like computers, Smart phones, Smart TVs, HD DVD players, Satellite Dish Systems, and even PV systems. These are all susceptible to transient power surges. This hardwired RV surge arrestor also offers monitoring via LED lights - when the lights are on, you know you're protected. Our 5-year Limited Warranty even includes lightning strikes. Orr standard hardwired unit also features circuitry encapsulation to protect against moisture and vibration - a necessity for those who chose to live life on the open road.