Position the DMR Series digital radio callbox virtually anywhere to maximize efficiency and improve safety or service response times. Deploys easily ? no wires, no trenching, no construction required. Can be used stand-alone using alkaline batteries or can be powered using external AC adapter. The DMR Series callbox provides crisp, clear, long-range 2-way voice communication, permitting co-workers and visitors to communicate with your DMR radio-equipped staff from points near and far? be it from the plant floor, maintenance garage, gated entry area, delivery dock or the parking lot.