Surge Guards Model 44290 Surge Protectors are prefect for pop-ups and travel trailers, identifying faulty park power and protecting from surges. Its easy-to-read LED fault chart provides simple power analysis while it test and indicates for the following: Open Neutral, Open Ground, Reverse Polarity, Open Circuit/No Power, Missing Leg 1/Missing Leg 2 Voltage, Surge Protection Status, and Overheating Plug/Receptacle. Its increased receptacle brass thickness reduces heat naturally. Each plug features a convenient Easy-T-Pull handle.