The E61 part is a form of old-style electro-mechanical contactor, used to control the operation of electric motors, lighting, and other loads. It is composed of a removable cover, contacts, coil, and mounting plate. It functions by using an electromagnetic coil to mechanically open and close electrical contacts to switch a load on or off. The contactor can be operated via a manual switch or an external power source, such as a timer or relay. This type of contactor is still widely used in industrial, commercial, and residential applications.