Someone help please...Progressive Industries EMS-HW50C

A long time RVer recommended the Progressive Industries unit, he had tried many other power protection units over the years. It works! Senses low, high, missing neutral, no ground and frequency and LED shows error codes. Several neighbors lost refrigerators, microwaves, TVs and invertors. Watched several people get shocked - missing neutral at the pole. I would find another serviceman who owns a TT not just a tent and flashlight.