Sentry HO490 metal stereo ear buds feature soft silicone ear-pads and an ergonomic design that fits the shape of your ear; extra ear-pads for easy replacement; noise reduction; extra bass, 9mm driver; frequency range: 20Hz-20kHz; impedance: 16 Ohms; 4 foot cord length with 3.5mm audio jack. Great to use with iPhone, iPod, Blackberry, MP3 player, games and more.