Columbia Mens PFG Backwater Short Sleeve Button Down ShirtThis lightweight button up PFG shirt is built with sweat wicking soft feel fabric, UPF 50 sun protection, and back ventingmaking it an easy, wear anytime essential for long summer days. Product Details: Omni Shade UPF 50 guards against skin damage using tight fabric construction and modified fibers to block UVA UVB rays, so you stay protected in the sun Omni Wick keeps you dry and cool by pulling moisture to the fabrics surface to evaporate,