The Carhartt Duck Zip-to-Waist Biberall is Quilt Lined for warmth and comfort on the job. Made of 12-ounce, rugged 100% cotton duck, it's lined in a midweight nylon-quilted polyester. It features zip-to-hip leg openings with wind flaps and snap closures and double knees with cleanout bottoms to accommodate knee pads. Main seams are triple-stitched for durability. *12-ounce, heavyweight, 100% cotton duck *Quilt Lined * Double knees with cleanout bottoms to accommodate