The Patagonia Women's Fore Runner Zip Neck Short Sleeve Jersey features lightweight recycled polyester for the utmost in moisture wicking comfort during grueling runs and long distance trail rides. It's Bluesign approved, so you can wear it proudly knowing it uses sustainable materials without harmful production processes. The 10 inch zipper facilitates maximum ventilation when you're pushing your body to the limit, and there's even a soft chin guard to prevent the scratchy, irritating feel when it's fully zipped. Polygiene odor control prevents the build up of funky microbes throughout the life of this performance top. Other functional features include minimal flat seam construction for a smooth, non irritating feel, set in sleeves for maximum mobility, reflective details for high visibility, as well as a UPF 15 rating for protection from harsh UV rays.