Sun UV ProtectionSun protection arm sleeves with the newest UPF 50+ protective technology for effective UV protection,whick can block out over 98% of harmful UVA & UVB rays to offer your arms an all-around UV protection. Say goodbye to sunburn & sunscreen Superior Cooling: The specially designed with ice silk fabric, which helps to cool your skin for 3 hours after absorbing sweat or water. It is the exact provides you with the cooling and comfortable feeling throughout the whole hot days. Durable & Easy To Clean Reusable and machine washable. Made from seamless microfiber polyester to provide lightweight durability, wrinkle resistance, stain resistance, as well as great stretch and flexibility while always retaining its shape. Breathable & Comfortable To Wear The quick dry fabric technology lets your sweat band dry in minutes.It provides customers excellent wearing experience with breathable and stretchy.The moisture wicking fabric seamless bandana makes you feel cool and comfortable, and keeps you cool in the summer and warm in winter. One Size Fits MostThe natural length of men & women arm sleeve is 15 inch and max stretches to 47 inch. the upper arm circumference is 3.7", max stretches to 8 inch.They are durable and stretchy, great fit for all shapes and sizes and teenagers as well as adults of all ages.