The Nike Amplified Elbow Sleeve 2.0 offers your arm excellent support and impact absorption, and it was constructed using Dri-FIT fabric that wicks away sweat to keep you dry and comfortable. It also features a mesh panel on the inner elbow for extra ventilation. Utilized neoprene for impact absorption and support. NFHS Compliant. Sold in pairs. Sizing: Measure around the widest part of your forearm. Small: 9.4" - 10.2" Medium: 10.2" - 11" Large: 11" - 11.8"