"The Patagonia R1 Pullover Jacket is the aerobic-output option of the R1 line. The pullover silhouette closes off the chest entirely, which keeps cold air from channeling in during sustained effort the way a full-zip can. HeiQ Pure anti-odor treatment means it stays fresh across back-to-back days without needing a wash between ski tours or climbing trips. What Our Gearhead® Experts Are Saying:""I wear this on the skintrack and under a shell on cold climbing days because the pullover cut seals out drafts at the collar without the bulk of a full zip. The Polartec Power Grid grid structure moves sweat off fast enough that I'm not soaked when I stop moving."""