Ihave not been very happy with the product, very happy with the supplier, and delivery, etc, maybe I did not read enough before I ordered, but, do not get very warm, take a long time, to heat up, and was looking for something, that I could put in gloves, boots, that would really help, and these, just don't do that. Again, probably my fault, for not reading enough about what they would do, And , again, the seller , I do not blame at all. I should have done more research, etc. I am not returning them, and going to use, them, but, guess, I should have known, that for the price I got them, they were not going to be huge feet and hand warmers. It was my first time, looking into products like this, and thought, oh great, just put them in my gloves and boots, and will stay warm all day. They actually, seem to me, to get warmer, if left outside, in the air, for long periods of time, seem to lose heat in gloves, etc. Said they were air activated, so maybe they do better, just left outside, and then, put in. I don't know.