Sennheiser Electronic Corp.","The successor to the hugely successful PXC 250 is here-- the brand-new PXC 250-II improves upon the previous model making it our best value yet.The mark II on-ear, collapsible mini headphones are equipped with NoiseGard™ technology to cancel droning, fatiguing airplane or bus cabin noise. They are also equipped with a convenient in-line volume control which enables the listener to adjust playback volume even when the music player is stowed.The PXC 250-II headphones are foldable and also function as normal headphones without NoiseGard activated. A single AAA battery provides up to 50 hours of NoiseGard performance. An extensive set of accessories - in-flight audio adapter, carrying case and AAA battery- completes the package.