I heard volleyball players use these too. I opened the package after it arrived and wore it once to try it on. The size is L. The corresponding size is for a knee circumference of 46cm to 52cm, measured 10cm above the knee. It's getting cold, and it's the season when knees start to hurt, so I recommend these for men in their late 40s and early 50s. Also, they are very thin, so they are not noticeable under a suit. They are sold for around 1700 yen each. I will sell two, one for each leg. I accidentally bought L instead of LL. I only tried it on once, and since I don't have the box, I'll list it as having no noticeable scratches. I will pack it in the box for the LL size I repurchased when I ship it.