The KDX/200 is a high quality aluminum isolation earbud that delivers accurate acoustic reproduction in a compact and comfortable design. The KDX/200 features a dynamic element that is positioned just outside the ear for extended frequency response. The KDX/200 includes small, medium and large silicone ear cushions for a customized fit to enhance isolation when you want to eliminate ambient sounds that interfere with the listening experience. A convenient carrying case for protective storage is included. Built to last, the KDX/200 is covered under the Koss’ No-Questions-Asked Lifetime Warranty - the only warranty of its kind in the stereophone industry.