Amron's line of Rack Mount Communicators are the most versatile and powerful communicators on the market today. The most unique feature is the design of separate channels and volume controls for each diver and the tender, both for the up-link and the down-link paths.You can set the volume for each diver and tender to their individual comfort level. Both divers can be set up on 4-Wire or 2-Wire mode, or one diver on 4-Wire and the other diver on 2-Wire mode, or any combination of the two modes. Comes standard with rear mounted MS connector, providing connections to diver and tender inputs and outputs. All rack mount radios include a hand-held, push-to-talk microphone.