Plantronics DSP400 Foldable Multimedia Headset Inline digital volume and mute controls for easy access Built-in digital signal processor provides enhanced, full-range stereo sound Folds easily for convenient storage Multi use stereo headset with built-in microphone USB plug and play compatible--no sound card required Multi use stereo headset with built-in microphone Folds easily for convenient storage USB plug and play compatible--no sound card required Built-in digital signal processor provides enhanced, full-range stereo sound Inline digital volume and mute controls for easy access