Arcteryx says about the Gamma Jacket Men's
Durable, comfortable Wee Burly™ Double Weave fabric resists wind and water, and has excellent stretch | Brushed backer adds light warmth and comfort next-to-skin | Vislon front zipper with wind flap and chin guard for added comfort | No Slip Zip™ prevents inadvertent opening | Zippered chest pocket and hand pockets for secure, accessible storage | Semi-elasticized cuff for a secure, comfortable fit | Adjustable hem drawcord seals out drafts | High hip length for freedom of movement | Regular fit with articulated patterning for mobility and comfort