The APW 2E-63012 Amber Signal Light operates by reflecting up when electrical current is passing through the internal element, which means that a control circuit in the equipment is active when it is in operation. It consumes a little bit of power to keep it lit when it is attached to the wiring of the system. It is mounted on the front panel of foodservice equipment in a 1/2" hole. T... https://partsfe.com/2e-63012-apw-signal-light-12-amber-250v