Two of ZipWall's heavy-duty zippers create a hands-free entry by simply rolling up the flap and holding the door open using two flap hooks. This hands-free door can be as wide as needed to get equipment and supplies in and out of the worksite. The patented ZipperKnife sheeting cutter that comes with this zipper 12-pack prevents jams and is designed to double-cut the plastic, leaving a clean cut that keeps plastic away from zipper teeth. Each ZipperKnife will make up to 100 cuts.