For use with Power Acoustik(R) Mobile A/V systems; Single-channel IR wireless headphones with swiveling, fold-flat earpads; Adjustable straps for maximum comfort; On/off switch saves battery life; Auto off and auto mute; Variable volume control; Auto level control; MP3 player input via 3.5 mm input; Includes 2 AAA batteries, FM transmitter, and EVA hard carrying case; 2 pairs;