For the casually athletic, or just the plain casual. This quarter zip is soft, breathable, and has added stretch so it's perfect for working out, or hanging out. We took our insanely light and breathable Air fabric, and made it slightly thicker for our outerwear styles like this. Don't worry, it's still incredibly comfortable and stretch just like the original. Paul is 6'2", wearing a Medium, and brings his dog Malcolm to every photo shoot.