Compucessory Metal Stereo Earphone 9mm metal earbuds have a real metal touch and feel. Driver is designed for powerful bass delivery. Earbuds feature 20-10KHz frequency response, and 16 Ohm impedance and a sensitivity level at 1 Khz, 88db. Earbuds come in three ear cushion sizes and include a 3.5mm plug and 4' cord.