I purchased this switch for use in an on/off application in a line powered (120 Volt..) project. It is a double pole switch so both the power "hot" lead and the "neutral" can be effectively switched. In most cases there is no real reason to switch both legs of a 120 Volt circuit. In most cases it just adds a little redundancy to the switching circuit. There are, however, certain applications where double pole switches are very popular.... it just wasn't really necessary for my use. Nevertheless, I chose this switch because of my familiarity with Gardner Bender. I felt certain that the switch would be high quality and would handle many on/off cycles. This bit of added confidence on my part made the choice an easy one.