This 400 Hz Facility Converter, the ‘Mayport’, is specifically designed for harsh weather outdoor use. It’s Harsh Weather Enclosure was designed for the Mayport Naval Air Station in Jacksonville, Florida. The Mayport’s enclosure has two compartments; one is NEMA 4 and one is NEMA 3R. Anticorrosion features are incorporated throughout so the Mayport will remain free of rust and corrosion. When your ground power equipment is permanently installed outdoors, the Mayport is the model you need.