Excellent sound, pure and clear with very low current and pleasing to the ear. Easy to install. Can be paired to two devices (mobile + bluetooth transmitter for example). Equally effective for headphones that mobile hands free. Ideal with htc touch hd. I just regret that when put in the bottom of a bag, he can get back into road alone (press the button on) and ten times remember the last party (press the same button, which also serves as a reminder). To avoid this disappointment, it is best bluetooth off after use, or if you do not use the hands-free function, disable it.