The Koss CS100 USB communication headset boasts a full range of sound that brings every conversation to life. Hands-free communication via an electret, noise cancelling microphone, is combined with high noise sensitivity and reduced sound distortion for clear conversations. The USB plug provides quick and easy connection to your PC. Whether your primary use is for telecommunications, voice-activated software programs or indulging in multi-player video games, the CS100 USB headset offers long-lasting comfort and crystal clear communication. Communication made easy, with the Koss CS100 USBCan be used with an external power source if sound card does not have built-in bias supply.