These collapsible mini headphones are equipped with NoiseGard technology to cancel up to 80% of airplane or bus cabin noise without added bulk or size. They are also equipped with a convenient in-line volume control that 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. These headphones come with an extensive set of accessories, including: an in-flight audio adapter, a carrying case and a AAA battery.