You needn't be held captive by a headphone cord to listen to your TV, radio or stereo system, CD player or without disturbing others... these headphones are wireless! First plug the infrared transmitter into the "tape, aux or mono" or headphone jack of your stereo or TV. It then transmits the sound to the lightweight wireless headphones. Go about your business anywhere within 40' and within sight...the infrared transmission assures static-free, interference-free sound. Meanwhile your spouse can sleep or read without hearing a thing! Includes volume controls, on/off switch, and all adapters to work with any TV or sound source, and a mic adapter for use with older TVs that have no audio output jack. 3" x 2 3/4" - dia. transmitter includes stereo cable, Y-adapter, charging cable, plug adapter, and UL-listed AC adapter. Two AAA batteries (not included) required for the headphones.