I use the headphones with a Samsung S4 while jogging or walking. My Samsung is in a leather sleeve and in the pocket or jacket pocket. Under these conditions, the connection is very, very often interrupted my Samsung S4. So the Kofhörer are useless. If the Samsung without shell, is kept out of the bag and on chest level, no or few interruptions. The sound quality is sufficient for audio books. The temples are not very stable from a cheap Kunsstoff us. Battery after 3 hours empty.
I have complained about the headphones and get a replacement. They work just as bad as the first.
Now I bought the headphones "Sony SBH20 Stereo Bluetooth Headset black". No interruptions, a much better sound quality. The Koplung with Samsung S4 works better and also the Koplung with my old Samsung ACE (that's with me deleyCON failed).
CONCLUSION: I've thrown away the money for delyCON praktich. The many positive reviews, I can not explain it.