Stereo Neckbands are designed to be worn behind the neck and ears. Ideal for portable CD, DVD, MP3 players and iPods. Lightweight behind-the-head design features a soft-touch rubber 4' cord and a 3.5mm straight plug. Headphones offer 32ohms impedance, 30mm drivers, anisotropic ferrite magnet, 0.016mm film, 13.6mm coil, 100 dB +/- 3dB sensitivity, less than 3dB channel balance, 40mW rated input, 100mW maximum input and 20Hz to 22,000Hz frequency response.