I bought this for double hip replacement and I'm very glad I did! It was easy to use and will stay cold a whole day or night depending on how much you use it and I used it a lot. First on one hip, then on the other, then back again for hours. Saves you, or your caregiver the hassle of filling ice bags or refreezing ice packs constantly, especially at night. You can adjust how cold you want it and the motor was very quiet. It's very well made, user friendly and does not leak or sweat. I'm sure it's the reason that I was pain free for much of my recovery and my swelling was reduced considerably. Although I bought the large shoulder pad, because it came with the unit, it worked perfectly fine on my hips. It's already being used by other members of my family for a sport injury, so worth the investment.Tip - we used three frozen bottles of water along with the water and filled the remaining space with ice cubes. We think it made the ice last longer and you can just throw the bottles back in the freezer when you change it up to a fresh load.