Our Carhartt R27 sandstone duck bib overall will keep you warm all day. Made of 12-ounce, 100% sandstone duck, it is lined with a midweight, 100% quilted nylon polyester. It features double knees with cleanout bottoms to accommodate knee pads and has zip to knee leg openings with a protective wind flap. It also has several tool and utility pockets, a hammer loop and brush loop. Back pockets are reinforced for durability.