EN3® Connectors Switchcraft EN3® Connectors are specially designed for harsh environments, meeting enclosure ratings of IP66/IP68 and NEMA 250 when mated or covered. These connectors feature an integral O-ring/gasket and 2-18 pins/sockets in the same housing size. Switchcraft EN3 Connectors come in a variety of options, including right angle, quick disconnect, and straight with and without strain relief. Applications include marine, medical, food service, transportation, GPS, and general electronics.