Fabric:Sunscreen arm sleeve fabric is engineered for cutting-edge performance and comfort, including our exclusive technology that accelerates moisture wicking for a cooler workout and helps keep the fabric fresh Soft, lightweight, breathable, moisture wicking and quick dry to keep you active all day. Made of cooling prototype silk: Using innovative cooling technology and UPF 50 protection, it can block more than 98% of harmful UVA and UVB rays.After wearing in summer, it will make the skin feel cool and no longer need to use sunscreen.But in winter, it can also warm your arms, yes, it is so amazing. Seamless and comfortable: using seamless technology, it will not leave a mark on your arm.Quick perspiration and fast drying will keep your skin fresh all day long. Practical and durable: Our sleeves are very durable and elastic.The elastic upper strap securely holds the cover in place, while the thumb hole helps protect the hand and provides an excellent solution for temporarily covering the tattoo. Suitable for all sports and outdoor activities: our lightweight sleeves are designed for long hot days in the sun, whether you are running, playing golf, fishing, playing basketball, cycling, hiking, driving or even gardening, Both can make you feel comfortable. 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.