The Nike Pro Knee Sleeve with Strap is a great option when you need extra support while exercising. With a breathable stretch construction, this knee wrap provides lightweight compression support with adjustable closures for a customised fit. With Dri-FIT technology Adjustable, low-profile straps allows you to customise support level Light compression and breathable mesh provides comfortable support Easy pull on design 30% polyester, 30% neoprene, 20% thermoplastic rubber, 10% nylon, 10% spandex Sizing. Small (36-38cm), Med (38-43cm), Large(43-50cm), X-Large(50-55cm) Measure the circumference at the centre of the knee. Your knee should be slightly bent.