Sennheiser pxc250 ii headphones highly portable travel headphones such are the pxc 250 ii mini headphones with noisegard active noise cancellation technology they also come with a closed supraaural design which provides for excellent passive attenuation of ambient noise adding to this the newly improved battery pack requires only a single aaa alkaline battery it lasts up to 50 hours more than enough for your return flight from tokyo to new york features noisegard active noise cancellation