The 28-C-120A product is a digital time switch manufactured by Guardian Electric. It is designed to provide digital time control and switching of AC loads. It has a time range of 0.1 seconds to 168 hours, and can operate on 120V/60HZ AC line voltage. The 28-C-120A can be connected to a variety of devices such as contactors, relays, and motor starters. It is designed to be mounted on a standard electrical panel and is UL Listed. This product is a great choice for controlling water-heaters, HVAC systems, lighting circuits, and for heavy industrial switching applications.