Do not work with my Samsung Galaxy S4: 1) Bluetooth Connection OK. 2) Button answer / end OK (therefore well connected) 3) But no sound, and regardless of the volume setting! Yet the "Audio for calls" function is activated and the sound should reach the listener (confirmed by message "connected to the audio system of the phone"). Another product toc? I have a Jabra Halo Bluetooth headset that works very well for 2 years ... Back Amazon!