With NoiseGard active noise cancellation technology, Sennheiser PXC 250 II is a highly portable travel headphone. They come with a closed, supra-aural design which provides for excellent passive reduction of ambient noise. Adding to this, the newly-improved battery pack requires only a single AAA alkaline battery, which lasts up to 50 hours. These sleek headphones are suitable for all types of modern music. The steel-reinforced headband ensures high durability. It also has an integrated volume control for enhanced usability and convenience.