The NEMA Type 3S, 3X, 3RX and 3SX electrical enclosures have the same level of protection as the NEMA Type 3, but have one large distinction. While the Type 3 and 3R are constructed and formed of either 12 or 14 gauge steel, the 3S, 3X, 3RX and 3SX are molded from either Polycarbonate or Fiberglass. 

The enclosure is gasket sealed and offers protection for personnel and from falling dirt, windblown dust (3RX has louvers and does not protect fro blowing dust), water, rain, sleet, snow and ice. Because the Types 3S, 3X, 3RX and 3SX are made from Polycarbonate or Fiberglass, there is an additional level of protection from corrosion.