HP-11S headphones feature an adjustable swiveling over-the-ear pad to reduce ambient noise. Each HP-11S headphone has independent volume control, and also 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. HP-11S can be used with any mobile entertainment device featuring a single channel Infra-Red transmitter. Requires 2 AAA batteries.