Headphones - headset, around the ears, closed construction, 3,5mm Jack, frequency range: 25 Hz-15000 Hz, sensitivity: 92 dB/mW, impedance: 32 Ohm, cord length of 2,5m The Koss UR/18 are very lightweight, comfortable, semi-open, mid-range headphones that come at a great price, featuring improved dynamic drivers. Closed, leatherette ear cushions ensure great bass and block out ambient noise. The adjustable headband guarantees a perfect fit, and the foldable design makes the headphones easy to transport. The Koss UR/18 headphones are covered under the manufacturer's standard 24-month warranty.