This is the Neosport Men&';s Short Sleeve Hyperflex Loose Fit Rash GuardFeatures: Flat-lock seam stitching for breathable, chafe-free wear Surf T-Fit - loose and comfortable UV Protection Great protection against sea lice, jellyfish, and rashes Spandex/Nylon The Neosport Men&';s Short Sleeve rashguard keeps your skin safe in the sun and offers extra coverage when swimming. It is lightweight, breathable, and has flatlock seams for a comfortable fit. Protect yourself without sacrificing quality or style. The Spandex/nylon LOOSE FIT rash guard is designed to fit loose, similar to a T-shirt. It provides excellent UV, rash and jellyfish protection. UV rating varies by color of actual shirt - the darker the color of shirt, the better the UV rating. These shirts are a great first layer under wetsuits or a great stand alone shirt for the beach, lake or pool. Order the same size as your wear in a t-shirt for a loose type fit. For layering under a wetsuit, we recommend going down one full size from your normal t-shirt size.