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 elbow. The lightweight elbow support 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.sizing: measure around elbow Small: 7 - 9" 18 - 23 cm Medium: 9 - 11" 23 - 28 cm Large: 11 - 13" 28 - 33 cm X-Large: 13 - 15" 33 - 38 cm XX-Large: 15 - 17" 38 - 43 cm