✅ UPF 50 PROTECTION: The arm sleeves are made of premium soft fabrics, 70% Nylon and 30% Spandex. They can block out as high as 97% of harmful UVA and UVB rays to prevent sunburn, skin aging. No more Sunscreen. You are maximum UV protected all day long. ✅ COOL FEELING: Extremely elastic material cooling arm sleeves cooler than bare skin. Keep you feel cool in the hot summer. When you wear the sleeve, it will straight down 5 degrees. No worry be exposed to blazing sun. ✅ COMFORTABLE & BREATHABLE: High performance fabric can fast sweat kick-away and fast dry, ensure outstanding comfort and make your skin fresh all day long. The non-slip elastic bands on the top and bottom to confirm the sleeves won’t slip from your arms. Beister arm sleeves are suitable for most people’s arms, without any pressure or discomfort.