Schneider Electric's Square D heavy duty safety switch is designed to be tough, reliable and provide exceptional performance in the most grueling conditions. They have been designed to have a significantly higher durability than a standard switch and have a durability three times greater than NEMA standard making it ideal for all your commercial and industrial needs. All heavy duty safety switches feature a quick-make, quick-break operating mechanism, a dual cover interlock, and a color coded indicator handle. This three blade fusible heavy duty safety switch that is rated at 400 A with a voltage of 600 V AC/DC. This switch has a NEMA 3R/12 enclosure and comes with factory installed viewing window. The device accepts H,K,R fuse types as shipped and can be field modified for J fuses. All heavy duty safety switches are tested per UL98 and NEMA KS1 standards and listed in the UL files E2875 and E154828.