The Mens Arcteryx Rho AR Zip Neck Top is excellent for high output activities in cold weather. Made of Polartec Power Stretch, this Arc'teryx baselayer shirt offers excellent moisture management and great warmth-to-weight ratio. The revised fit of the Rho AR Top with the athletic stretch provide excellent mobility for active pursuits and the plush interior offers next-to-skin softness. Other features include chafe-free flatlocked seams, a zippered sleeve pocket for small items, and a mock neck with zipper for quick on/off and venting. The form fitting Mens Arcteryx Rho AR Zip Neck Top can be worn as an insulation piece or as an outer layer during cool weather workouts.