First of all, I bought these because I had purchased their earpiece before.  The earpiece was very, very good and light weight.  There was the problem.  They were so light weight that I would forget that I had it on and would knock it off, several times, rendering it unuseable.  So when I needed to replace it I decided to look into buying another Cardo Scala.  My cell phone is Bluetooth compatable and I bought a 2GB chip so I can download music and needed a stereo headphone set so I can listen to the music.  Since the Cardo Scala earpiece was very good (operating the buttons and voice and hearing quality), I decided on getting the stereo headset.  These are great!!!  The control buttons take a little getting used to, but the real nice feature is when you answer a call you hear the person in both ears (not stereo), which makes it easier to listen to the caller.  The one problem I have is the rubber rests sits on the skin between the ear and skull and after about six hours makes that area a little sore.