Most "heavyweight" sweatshirts are 10oz-12oz. We decided to double it and then some to create a truly heavyweight and super warm sweatshirt. Two layers of thick, 13 oz. 100% pre-shrunk Cotton Fleece for warmth, and gusseted armpits for freedom of movement. Snap closures at the neck keep the neck and chin warm while the oversized hood fits over a hard hat or helmet. Vertical, recessed handwarmer pouch to keep dirt and grime out of your pockets. Basically, it's the most well thought out and best made sweatshirt ever.