I've been on a quest to find the right earbuds for running and this is my 7th set. I decided to try a single earbud because I'd like to be able to hear what's going on around me when I'm running and it's difficult with a standard pair of earbuds. This earbud is amazing. It is the most comfortable I've used. It has numerous cushions (7 I think) to find just the right fitment. The earbud itself is small and very comfortable. I was able to find a cushion that allowed the earbud to fit snuggly without being uncomfortable. The sound is fantastic and there's no external noise or "whooshing" in the ear with the earbud. The cord is about 6" shorter than I would like, but it's not a deal-breaker. The button works well and I can play/pause/skip my music on my Android phone. I haven't tried the mic yet. The only difficult part (which is not the fault of the earbud) is simply getting used to sound coming from one ear instead of both. In just a few days, it doesn't seem strange and I expect in a few more days it will seem perfectly normal. To clarify a point about the earbuds (this was confirmed with JLabs): The earbuds DO play stereo sound through the single earbud. It combines both channels into the single earbud. I assumed that was the case, but the description was unclear so I asked before purchasing. The sound really is fantastic. One of the best purchases I've made. Now I just hope they hold up to the abuse of running 4-5 times/week.Update after a LONG time of usage: I have come to depend on these earbuds. I use them multiple times a day for audio/video conferences as well as music and videos. I've gone through 3 pairs ONLY because I accidentally misplaced them. I am obsessive about my earbuds, but it has happened. I've always replaced the exact model just fine. However, when this happened a few weeks ago, Amazon indicated they were no longer available. I was crushed, but ultimately thought... they are just earbuds. I researched a ton and ordered a different brand. Ugh. Awful. All kinds of sounds from it wiggling in my ear regardless of what size cushion I tried. Button was crap. I looked on Amazon again to check for these and OMG, they were available. Came two days ago and I couldn't be happier. Seriously, these are the best.