The TKS Titan Knee Sleeve is a neoprene sleeve perfect for supporting your knees during training. I bought it on Mercari. It was listed as a size L, and I naively assumed it would fit since I wear L, but it was actually too tight and I couldn't wear it. According to the official size chart in image 9, size L is for a knee circumference of 38-39cm, and unfortunately, my knee circumference measured approximately 42cm. The size L is also indicated in image 3, though it's small. I haven't worn it at all, but as you can see in images 8 (left side) and 12 (right side), cracks are starting to form inside the material on the back, so I'm selling it at a bargain price. The seller said it was still okay, but please understand this before purchasing. - Brand: TKS - Model Name: Titan Knee Sleeve - Accessories: Comes with a storage bag - Material: Neoprene - Size: Free Size No pets. Non-smoking. Thank you for looking.