I used one of these 25 years ago, after arthroscopic surgery for an ACL replacement and meniscus cartilage tear. I needed to replace that one after it became brittle and started leaking. The medium knee cuff fits perfectly for my size and within just a few days, my knee's swelling from overuse has nearly returned to normal. In fact, I am back to doing all my exercises, and just need cool it in the down time. Kudos to MyColdTherapy for immediate shipping, and one of the best prices out there. Many grateful thanks.