*** Disclaimer: I have never been offered any monetary incentives or discounts by sellers on Amazon to write positive reviews, nor have known that to happen. This my honest review. *** I use Ice Roller for chronic TMJ, migraines, severe thumb arthritis pain and neck stiffness (every 15 minutes until it is room temperature). After use, I wash it with warm soapy water, then make sure it's fully dry before I put the entire Ice Roller into a large Ziploc storage bag into the freezer. The roller is easy to snap on and off if you would rather freeze it by itself, but I like to keep it all together (plus there's the wear and tear of constantly removing it). Earlier this year, I visited the orthopedic surgeon for a third round of a Methylprednisolone injection directly into the wrist for severe thumb arthritis, trigger finger and carpal tunnel. This time, I brought Ice Roller with me for additional numbing before the injection (I tend to have mild needle anxiety). In addition, the Ice Roller worked by easing some of the pain and simultaneously calming me down while I waited for the doctor to appear. I was pleasantly surprised that my doctor was so fascinated by how simple, effective and inexpensive Ice Roller is. He asked several questions, tried it out as he repeated that he "wished he thought of it first." He even said he would recommend it to all of his patients! I hope he did because it's a great pain management tool to have. Ice Roller is about the size of a hairbrush, though slightly heavier. It's perfect to bring to the office (if you have access to a freezer within view of your desk), or maybe while watching your child's gymnastics class in a hot, crowded gym. You get the idea! It stays cool longer than you'd expect.