Koss JR900s are the music lover’s answer to true stereo and cordless freedom. Operating on one of the highest power bands available on the market, the Koss JR900 headphone system (consisting of a high quality, battery operated RF transmitter with AC adapter) offers the best in wireless audio technology, allowing you to roam freely over a 70,000-square-foot area. From room to room, inside to outside, even in bright sunlight, you can move to your heart’s content without the need for additional transmitters or worry of signal breakup.