These Square D heavy duty safety switches are designed to provide exceptional electrical protection in the most grueling conditions. They have been designed to have a significantly higher durability than a standard switch. Some key features are their quick-make, quick-break operating mechanism, a dual cover interlock, and a color coded indicator handle. These double throw safety switches are able transfer a load from one power source to alternative power source economically. They adhere to the datasheet spectifications and have been certified by UL.