2XU Performance Compression Stirrup Calf Sleeve Featuring signature PWX (power, weight, and flex) Fabric Technology creates a perfect equilibrium in the 2XU Performance Compression Stirrup Calf Sleeve. The medically engineered circular knit fabric structure supports the shin and provides consistent pressure for muscle containment. The sleeve is lightweight, quick drying and breathable, with moisture management to wick away sweat, all combining to produce optimum comfort. Additional treatments gives the sleeve SPF 50+ sun protection and an antibacterial enhancement. 80% nylon/20% spandex. Imported.