Sennheiser  MX 660-S High Performance Dynamic Basswind Earbuds with Volume Control (Silver) Powerful, bass driven, stereo sound earphones High-performance dynamic driver system with Sennheiser "Basswind" system Frequency response: 18 to 23,000 Hz Volume control integrated in the cable and cable winder for easy cable length adjustment Ideal for use with all MP3, CD, DVD players and portable gaming systems