Camco PowerDefender Circuit Analyzer With Integrated Surge Protection and Indicator Lights, 30 Amp Male to 30 Amp Female (55310) Protect your electrical equipment from improperly wired electrical boxes Diagnostic lights indicate faults before you connect your electrical cord Voltage analyzer with surge protection up to 1050 Joules 30 Amp Male (NEMA TT-30P)/30 Amp Female (NEMA TT-30R) Contoured grip makes unplugging easier