MEElectronics M21-BL In-Ear Headphones for iPod, iPhone, MP3/CD/DVD Players (Blue) (Discontinued by Manufacturer) Driver: 6.8 mm dynamic drivers Frequency Response: 20Hz-20kHz Sensitivity: 92 dB Impedance: 16 ohms Accessories: 4 sets of eartips (small/medium/large silicon; bi-flange), clamshell zipper case