UV Protection: UPF 50+ sun shirts protect your skin from harmful rays. Breathable: The fabric offers superior function with moisture wicking that will keep you cooler in summer. 1/4 zipper: 1/4 zipper design, easy to put on and take off, and also provides extra sun protection for your neck. Details: Soft fabric combined with flatlock stitching reduces friction against the skin, making it more comfortable to wear. Occasion: The men's long sleeve shirt is perfect for fitness, running, hiking, fishing, seaside, sailing, travel and other outdoor activities.In order to fit you well after purchase, we use standard US sizes, we suggest you refer to our size chart to choose your favourite t-shirt.