Complete electrical protection for your RV! Automatically shuts off the power when detecting incorrectly wired pedestal, power surges, low (<102V) and high (>132V) voltage, reverse polarity, and dangerous current on ground wire. Automatically resets on power restoration. Features caution indicator light to indicate cause of power stoppage. 2 minute 16 second reset delay protects AC compressor. Offers 1750 joules of surge protection. UL Listed.