The ANC27 is a full-size ear cup, active noise cancellation headphone. Blocking out 85% of ambient noise, it boasts a powerful sound with supreme comfort. The ear cups are designed to fit well over the ears to provide comfort for hours, especially while travelling! One AAA battery alone provides up to 30 hours of active noise cancellation, but these headphones can also be used after the battery dies and without switching on the noise cancelling. These headphones include a hard travel case, an airline adapter and hi-fi jack.