JVC developed a 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 headphone uses a 40mm neodymium driver in each earpiece. For comfort and portability, the JVC 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 0.25 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.