The Surge Guard 34931 provides total electrical protection for your 30-amp RV, including protection against wiring issues; reverse polarity, open neutral and open ground. Also protects against low/high voltage, low/high frequency and elevated ground line current. Ten-second start-up sequence and 128 second fault delay sequence protect compressor motors against damage. Works with Surge Guard Wireless LCD Display (sold separately). A security ring on the cord lets you lock the Surge Guard to prevent theft. Comes with Southwire's Limited Lifetime Warranty with Connected Equipment Coverage.