The MC-MD 2 is a secondary unit to the MC-1. If you are looking to add a 2nd screen to your MC-1, this is it! Easily connect using the included MC-MD Y Cable and 8 foot extension cable. Additional 8 foot cable (MC MD EXT) available for purchase resulting in a 16 foot possible length. Need more? Connect up to 2 MC-MD 2 units to your media center. Personally customizable to store your favorite sources & favorite audio pre-sets for all 4 zones. Users can set multiple volume levels for a variety of lifestyle environments, then custom label those presets for fingertip access while on the water.