This is a used item. It was purchased at a chiropractic clinic, so it has considerably more support than commercially available products. Because of that, it requires some strength and technique to put on. I am selling it because I no longer need it (^ ^) I did not use it for a long period. Worn for less than 1 month, excluding when sleeping. It will be shipped via Yu-Packet Post, so the box will be flattened. Size S Knee circumference: 31 to 35 cm Product Number: 31951