The HA-NC100 is a noise canceling headphone that can produce a 75% noise reduction when in the active mode. It also has 50 hours of use on one AAA battery. The HA-NC100 also has a cord rewind system, so that it will retract its 4.9 foot cord back up into its left earpiece. And to make it easy to travel, the HA-NC100 folds down into a compact size for easy traveling and it comes with an airplane adapter and a carry pouch. And when you are not traveling the HA-NC100s can be used in the passive mode for great performance at home.