The new JVC HA-NC250 combines outstanding sound quality with advanced noise-canceling and isolation technologies to provide a superior listening experience. The HA-NC250's noise cancellation circuitry includes feedback technology that constantly monitors the noise cancellation process. As a result, the headphones eliminate up to 85 percent of extraneous background noise. To further block noise, the HA-NC250 offers two JVC innovations that help isolate the listener from outside sounds. First, each earpiece employs a double housing structure for an extra sound insulation layer. Second, JVC developed a new technique for attaching the headphone's smooth memory foam cushioned ear pads to the housing that helps isolate background noise. The smooth pads also enhance comfort. These sound isolation features, for which patents have been applied, are especially important since the HA-NC250 can be used with the active noise cancellation switched off. For the best possible sound quality, the new headphone uses a 40mm neodymium driver in each earpiece. For comfort and portability, the HA-NC250 is one of the lightest headphones in its class, weighing just 5.3 ounces. It folds flat, and when folded is slimmer than most competing models. Included with the HA-NC250 are a slim carrying case, a four-foot detachable cord, airline dual plug adapter, and quarter -inch plug adapter for use with many home audio and video components. The headphones use a single 1.5-volt AAA battery for powering the noise cancellation circuitry. Battery life is rated at about 50 hours.