UPF 50 UV PROTECTION COOLING ARM SLEEVE: The arm sleeve is made of high-quality soft fabrics. 70% nylon and 30% spandex. It can block up to 99% of harmful UVA and UVB rays to prevent sunburn and skin aging. No more sunscreen. You are maximally protected from UV rays all day long. Cooler Feeling: Extremely stretchy material, the cooling arm sleeve is cooler than bare skin. So you feel cool in the hot summer. When you wear the sleeve, it will drop five degrees. Don’t worry, the sun is burning. Closure: No closure Nylon. Spandex Sport Care Instructions: Hand wash only Model Number: BI-AS-001-3B-JF