Automatic transfer switch with full electrical protection from Southwire (R) is designed with dual 80A Chint contactors that include a mechanical interlock to ensure safe operation. The mechanical interlock design prevents both contactors from engaging at the same time. The rugged plastic box provides a safe and secure enclosure for the transfer switch device. Avoid the potential of corrosion, sharp edges, and risk of an energized enclosure that comes with a metal box.