Excellent, especially when gardening and driving.
Works really well, wish heating element was longer. I use this most often when I work outside (gardening and crafts) and start to get discomfort in my lower skull/upper neck from chill. Have also used in house for same pain, since it's more easy  to focus than electric pad and less fuss than microwave ones.  Like many people, I already have a couple of USB outlets and cables near the bed, so it's easy.<br />Both settings work well.  Vecro closure is mixed blessing...if I want to strap it on very tightly (to get good pressure on needed area), it is staff under my chin, so not as comfortable.  But, the design is fine when you just want warmth in the general area of your upper neck/shoulders.  I only wish the large disc-shaped heating element was longer (more like a rectangle).  Width of heated area is fine.<br /><br />Be sure you have a couple of USB battery banks that fit the pocket if you want to be truly portable.  I bought some nice ones, used, from Amazon warehouse.<br /><br />I originally bought this to use in car as well, since I get the same pain at night when driving.  But, now I'm just going to buy a second one, so I don't have to remember to pack it each time.
Rating: 5 stars