Listen to music from your PC, MP3 player, or entertainment system with HP's Bluetooth Pendant Headphone. You can wear it in a shirt pocket or clipped on a belt. Use the Bluetooth Audio Adapter to transmit music wirelessly from any audio source with an audio-out port: MP3 players, notebooks, CD players, etc. Small and lighweight for ultra mobility. Streamer and Audio Receiver can be used with other audio devices like your home stereo to transmit music wirelessly in the home. Includes high-quality earbud headphonesremovable for portability or for use with other headphones. Includes cable management widget to keep the headphones wires under control while active. Charge your headphones via AC adapter, or for use on the go, you can use any USB port to charge your headphone and adapter. Compatibility: Compatible with any notebook or desktop PC with a 3.5mm audio port (using included transmitter), and directly with any Bluetooth wireless technology enabled PC. Compatible with Microsoft® Windows Vista and Windows XP (SP2). System Requirements: Audio out port (headphone port) OR Bluetooth 2.0 with Enhanced Data Rate (EDR) technology enabled PC or handset. Audio in port or auxiliary port required to receive audio.