Sennheiser CX400-II (Silver) In-Ear Headphones with Dynamic Speaker System and Integrated Volume Controls High-end dynamic speaker systems with Neodymium magnets tuned for a natural sound reproduction Integrated volume control on cable Cable length 3.9 ft. (1.2 m)Symmetrical cable Optimized for MP3, iPod, iPhone, CD players and portable gaming systems Includes 3 sets of ear bud gels S/M/L, cable clip, cable winder and carry bag Frequency response (headphones) 17-22,000 Hz, Jack plug 3.5 mm. (angled) Impedance 16 Ohm