Well I have the Jabra 250 and it is good with my 7520. I did go out and buy the HS850 this weekend and the sound was great, call clarity was good, but I could not get the darn thing on my ear secure enough. No matter what I did it was really loose. So it is going back. I ordered a Tekkeon EzTalker Mini, all the reviews are good and the fit looks secure because it has an ear insert along with the hook. I will let you know. I am gonna sell this Jabra..its 1 month old..nothing wrong with it..just want the "blinking blue" disco light! lol