DESC: For Internet chat, telephony, speech recognition, video conferencing, music, and games, the Plantronics .Audio 40 stereo PC headset features a noise-canceling microphone for improved speech accuracy and clear voice transmission. The QuickAdjust telescoping microphone lets you place it perfectly for speech recognition. Enjoy music and multiplayer online games in full-range stereo sound. A lightweight, adjustable headband and soft, swivel-mounted ear cushions affords you all-day comfort. Compatible with popular PC sound cards, just plug it in and start talking, listening and playing. MacOS users may require an additional adapter.