This is a 50A 125/250V shore power inlet, most frequently mounted in the boat's cabin side or cockpit coaming.
The similar model 6373EL-B inlet includes a rear safety enclosure and wire strain relief; this model 6373EL does not.
• Easy Lock twist-to-tighten system
• Solid cast 316 stainless steel
• Soft Touch cap stays open in the upright position
• Locking waterproof cap
• Rear safety enclosure with strain relief covers wire terminals
• When closed, inlet exceeds ABYC watertight requirements for boat inlets
• UL listed, SA marked, 5-year warranty
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.