Stereo Neckbands are designed to be worn behind the neck and ears Ideal for portable CD, DVD, MP3 players and iPods Lightweight behindthehead design features a softtouch rubber 4′ cord and a 35mm straight plug Headphones offer 32ohms impedance, 30mm drivers, anisotropic ferrite magnet, 0016mm film, 136mm coil, 100 dB 3dB sensitivity, less than 3dB channel balance, 40mW rated input, 100mW maximum input and 20Hz to 22,000Hz frequency response