This is a plastic 50A 125V shore power inlet, most frequently mounted in the boat's cabin side or cockpit coaming.

Easy Lock twist-to-tighten system
Watertight cap
Rear safety enclosure with strain relief covers wire terminals
Marine grade, UV stabilized, white, glass-filled polyester
Marine stainless steel trim
When closed, all inlets exceed ABYC watertight requirements for boat inlets
ABYC Shore Power Warning Label decal available to go over stainless steel trim on 6351EL cover


Heavy on the technical side...

There are two categories of 50 Amp devices: 50A 125V (50A 3-wire), and 50A 125/250V (50A 4-wire).
The 3-wire devices have a single "hot" leg carrying 50A 125V.
The 4-wire devices have two "hot" legs, each carrying 50A 125V. (50A 250V when combined.)
These two categories are NOT interchangeable.
Never alter the plug of one type of these devices to fit into the receptacle or female connector of the other type.