Sennheiser PC 2 CHAT Mono Analog Headset for PC Sound pressure level (SPL) 95 decibel , Impedance 2 kilo ohm , Frequency response (Microphone) : 90  15000 Hertz Light and comfortable - with the lightweight headband, it's easy to forget you're wearing a headset Noise canceling clarity - thanks to the noise canceling microphone, your voice is easily understood without you having to shout Keep one ear free - ideal at home or in the office, the single-sided design keeps you in touch with your surroundings while you talk over the net Peace of mind - thanks to the 2-year international warranty Connectivity technology : Wired