I receive these as a gift from my partner and we have to exchange straight away as they did not sync. Then the next pair worked well for 3 months until the left ear bud wouldn't connect with my phone. I exchanged again as they are comfortable and have good sound when they work. The 3rd pair have now just stopped charging all together. Another 3 months after exchange. JB provide excellent service and have always helped but the headphones are not worth the money.