The Original American Stereophone Company ,Ever since we invented the world's first SP/3 stereophone back in 1958, Koss Stereophones have been bringing back the excitement of a live performance. Music lovers around the world recognize that dedication to accuracy in sound reproduction as The Sound of Koss. , ,The Koss CS100 communication headsets boast a full range of sound that helps bring every conversation to life. With high noise sensitivity and reduced sound distortion – not to mention hands-free communication via an electret, noise cancelling microphone – it will seem as if the person on the other end of the line is right in front of you. , ,Whether you employ telephony, voice-activated or voice recognition software – or indulge in computer games with sound cards that feature built-in bias supply* – CS100 headsets offer long-lasting comfort to accommodate the longest of telecommunications. , ,*Can be used with an external power source if sound card does not have built-in bias supply