First I took a risk on these bars because there was no reviews at the time and I was already returning bars from another vendor that did not fit well. I take about 4 steps and the start coming off. I also like tracking my heart rate to ensure Im in the fat burning zone. 2016 UpdateAfter 9 months of solid use, trying very very hard to love this device, I had adjusted an original 5 star score down to 4, and now down to 2. I’ve worn them for 1 day so far. Alright so I spent quite some time pouring over the reviews of various Bluetooth earbuds. He said they’re easy to pairs have great sound quality and a good battery life so he’s happy. Whether its to do with mobile phone use, or headphones, or pollution, its certainly aggravated by stuffing an earbud into my ear and backing up the wax and muck. If I had suggestions for Logitech:* Lit secondary legends* USB-C* PBT keycaps* User replaceable battery Only I can see it!