Norrona Senja cap is developed for trail running and will work great for other activities where sun protection and moisture management is needed. Norrona Senja cap is developed for trail running and will work great for other activities where sun protection and moisture management is needed. Norrona uses a lightweight warm1 fabric in this cap because it has great sun protection, is quick-drying and comfortable on the skin. The main fabric is a 100% recycled knitted polyester 140g/m2 with UPF 50+. The fabric is treated with HeiQ Fresh FFL anti-odor treatment. HeiQ Fresh FFL is a bio-based amino sugar polymer that is silver-free and not an antimicrobial. It removes the fat and protein from sweat, thereby eliminating the ability of the bacteria to grow and therefore reduce odor. Main features; flexible visor, a concealed key pocket, easy packability, and a built in sweatband on the inner rim to help reduce sweat from going into your eyes. This cap has an ergonomic cut with an adjustable buckle in the back.