I bought this to use while riding my motorcycle because the narrow profile makes it fit under my helmet. Usually I ride with the microphone / buttons on the outside of my helmet and then it's very easy to work the buttons with my gloves. If someone calls me and I'm not going too fast, I can tuck the microphone under my chin curtain and they can hear me no problem at low speeds (under 40). Very good cheap alternative to an expensive in-helmet bluetooth setup (I have that, too, but I end up using this more often).
Only downside is the battery life but for the price it's great. I would guess 2-3 hours talk time or 5-6 hours music-time on a fully-charged battery. Not as long as my SoundPeats or my over-the-ear headphones but considering the other benefits, I don't mind charging more often.