Skins Men's Bio Sport Sleeveless Top Nylon 76% / Spandex 24% Imported 76% Nylon, 24% Spandex Engineered gradient compression delivers more oxygen-rich blood to your active muscles - so you can train harder, play longer and recover faster. Stay protected. Permanent antimicrobial treatment, microfiber moisture wicking, and UPF 50+ sun protection help you stay dry and comfortable, dry, and performing at peak temperature in any conditions. Cold machine wash, gentle cycle, with like colors. Do not bleach, iron, or tumble dry.