With the Boss BV121MCH you can enjoy your favorite DVD videos as well as your CD audio & videos without having to go through the hassle of purchasing and hooking up a second unit to play your DVD/CDs through. Through the menu selection, the BV12.1MCH has the ability send out two different signals for your headphones to pick up, channel A and channel B. This feature works as long as your headphones also have the dual channel capability. For example, one headphone can pick up channel A and you are able to listen to your BV12.1MCH. If you have another video unit, you can just flip the switch on your second set of headphones to channel B and listen to that one. Both headphones can be switched between channels A and B to listen to either video source by a simple flip of a button on your wireless headphones.