Aiphone DA-1MD is a wired intercom system that allows for communication between multiple units. It features a call tone off LED that stays lit when the volume control is in the muted position, a call tone sounder, and a call tone volume control. The device can be used to activate door release and has a service button option. The DA-1MD is designed for use in areas with ambient temperatures ranging from 0°C to +40°C (+32°F to +104°F) and requires an AC 15V power source supplied from a power supply. It measures 200H x 89W x 63D(mm) and weighs approximately 350g.