This hs losses connection (too frequently) with my Siemens S55, it reconnects quickly but interlocutor hears me like a man into a deep hole. Very clear speaking reappears when I pair both devices again but for a short time until the hs disconnects again.Attachment divice hurts my ears even though this divice is so light.The manual is the poorest I have seen. Logitech's web site doesn't have online user's manual nor information about how to do the most common tasks like dial a number using the phone and then transfer the call to the headset, with my S55, first dial the number and inmediatly briefly touch the so called "multifunctional button" in the headset: warning!!! don't try to do this while you drive because you will need both hands to do this "impossible mission" maneuver.Battery life appears to be excelent (by now, I only charged it once, three days ago).