The Camco Power Grip Power Defender RV 50-Amp Circuit Analyzer with Integrated Surge Protection and Fault Indication helps protect your RV from power surges and faulty electrical connections. Diagnostic LEDs indicate faults when you connect your electrical cord to the power pedestal. The circuit analyzer indicates faults for reverse polarity, open neutral, and other wiring issues. Includes integrated surge protection of up to 2, 100 Joules. It's weatherproof and able to withstand adverse weather conditions. A contoured grip makes unplugging easier. 50-amp male (NEMA 14-50P) / 50-amp female (NEMA 14-50R). Patent pending. Circuit analyzer indicates faults for reverse polarity, open neutral, & more Integrated surge protection of up to 2, 100 Joules Contoured grip for easier unplugging | Camco 55309 Power Grip Power Defender RV 50A Circuit Analyzer