The HamiltonBuhl NC-HBC headphones are specially-designed to deliver superior noise-cancellation by actively reducing harmful and annoying low frequency sounds in noisy environments. The deluxe, over-ear cups with soft cushions deliver passive noise suppression as well. Together, the passive and active noise-cancelling technology creates a quiet, soothing environment to focus on the audio in your headphones or have some peace with no sound.The active noise cancelling (ANC) circuitry runs on one AAA battery (not included) and comes with a zippered carry case for protection and easy storage.Featuring an adjustable padded headband and a removable 5' Dura-Cord that can be swapped out for a 5' Dura-Cord with an in-line microphone to turn your headphone into a headset. Headset Dura-Cord is sold separately (NCHBC2).With it's active noise cancelling technology, the NCHBC1 is ideal for use with tablets, mobile devices and any unit with a 3.5mm stereo headphone jack.