Koss Porta Pro KTC Ultimate Portable Headphone for iPod, iPhone and iPad Ultimate sound and comfort for music lovers. Connectivity Technology: Wired KTC - remote and microphone control features made for iPod, iPhone, and iPod Adjustable Headband for maximum comfort Collapsible design for convenient storage, includes carrying case. Frequency response 15-25,000Hz, 101db SPL sensitivity, 3.5 mm plug