Not a good buy. I purchased one of these in hopes of relieving some sinus issues and it sits in my nightstand drawer unused. I tried to use it on my arm, didn't help there either. A sad sack of beans. I ended up falling in love with a clay cold-pack instead. I can't believe I bought this dumb thing. What a waste of money (and for people these days, money is important to save because everything else costs so much)! Effectiveness It didn't get cold! I put it in the fridge, it didn't get cold. I put it in the freezer, but it still wasn't very cold. I tried it anyway, fresh out of the freezer... and I couldn't feel anything. It was very disappointing. As I said, I bought a clay cold-pack and fell in love with that instead. Ease of Use The wrap part didn't really work well. I couldn't get it to attach well around my head, arm, leg, whatever. I thought, "I must be stupid!" but no, truly it was just a weird thing. It had a weird shape. Weird strap. No good.