wireless transmission protocol, to make sure that your listening experience is the best one, even at 10 feet from the original source. Sennheiser RS180: The RS 180 is a two-part system that comes with wireless headphones, powered by two AAA NiMH batteries and a transmitter that connects to your output device. We love the fact that it's very simple to set up, as the whole system is truly plug and play. Designed for sound fanatics, they can be set to individual preferences. Additionally, they also have automatic level control and the balance can also be individually adjusted. And the RS 180's multi-functional transmitter doubles as an easy-charge cradle and docking station. Now, that's convenient! Sony MDR-IF240RK Wireless Headphone: This wireless stereo headphone system, features 30mm drive units for deep bass, up to 30 hours of battery life on a single charge and a transmission range up to 24 feet. With an easy connection to your home audio system, TV or VCR, these headphones provide a lot of freedom to move around. 24-foot range is great for listening your tunes throughout the room. Infrared transmission works by sending out light signals from the transmitter to the headphones and are resistant to external noise and interference, but the headphones must be within line of sight of the transmitter, as the signal, can't pass through walls, furniture, or other obstacles.