This pair of headphones & transmitter package is a great solution if you have multiple entertainment devices in the vehicle with conflicting headphone transmitters. The small 900mHz transmitter module can be located anywhere in the vehicle, simply give the module power and audio signal from up to two DVD players, game consoles, or similar devices. Multiple users will enjoy uninterrupted sound from the selected device. HP-902RFT headphones feature an adjustable swiveling over-the-ear pad to reduce ambient noise. Each headphone has independent volume control, channel selector switch, and an auxiliary audio input to directly connect an iPod or other device with headphone output. A hardened plastic carry case is included for protective storage. Headphones require 2 AAA batteries. Use HP-900S for additional headphones.