The specialized manufacturing process of flat knit targets compression areas while still allowing the product to stretch and maintain a constant compression. The built in gel buttress supports the knee. The lightweight knee stabilizer helps to support the joint which can help improve performance and everyday activities. The unique design extremely comfortable materials and contoured fit make the sleeve comfortable to wear for extended play.For sizing - measure around the center of the knee:Small: 12-14" 30-36 cmMedium: 14-16" 36-41 cmLarge: 16-18" 41-46 cmX-Large: 18-20" 46-51 cm