SafeViewTM Power Inlets feature a smart circuit sensor that when you plug into shore power, you can see if your circuit wiring is good (all green lights). If there is a fault detected a dedicated letter (or two 50A) will light up red. G - Ground L - Line L2 - Line 2 N - Neutral Detects reversed polarityNickel plated contactsGlass impregnated fire retarding nylon plasticCustomizable stainless-steel faceplateHi-pot safe testing2-year warrantyRed/Green LED circuit fault lightsLED "Halo" backlight- solid white color is good, flashing red indicates an issue is detectedETL certifiedWeather ResistantAutomatic detecting missing ground, missing neutral, line and neutral reversed, etc.