Reliance Controls PB30 Power Inlet Box, 30A

The permanent, weatherproof way to get power from a vehicle or generator into a house — it mounts on an exterior wall and wires to a transfer switch, so nothing runs through a partly open door. One documentation caveat worth passing on: Reliance's own literature and most distributors describe this as UL listed, while at least one supplier states MET listing for the unit it ships. Both are recognised testing laboratories; verify which mark is on the box you receive if your inspector is particular.