"3 Dog Night" is an aboriginal expression for a night so cold, you need furry canine companionship in bed. Improved 3 Dog Base Layer Half Zip gives you that same warmth for frigid days on the job site. The 9-oz. 92% polyester/8% spandex Polartec® Power Grid™ fleece is now 35% heftier for St. Bernard-sized warmth. And its advanced grid structure reduces bulk as it increases breathabilty and wicking. Built for comfort in action with roomy raglan sleeves and side panels instead of chafing seams. Thumbholes for no-bunch layering.