It has a series of flaky behaviors with the 3650.  It is nominally compatible but in practice very difficult to make work.  The biggest problem is the phone won't ring when the headset is in "connected" mode.  It will just vibrate.  If you keep in in "disconnected" mode it takes 10-20 seconds to connect so better hope whoever is calling you waits a long time after you pick up (and there is no sound) and it doesn't go to voicemail.  Jabra tech support at first claimed it was a feature - "thats the way all headsets work" - yeah right! His suggestion was a) wear the headset all day long (you can hear the ringing thru the headset) b) keep the phone in your pocket all the time so you feel the vibration.  Then when pushed he claimed they are working on fixes.  It irks me that I bought this because [it is] listed ... as compatible, ...