ZipWall® Heavy Duty Zippers provide quick and easy access in and out of dust barriers. Each box of 2 zippers comes with the innovative ZipWall® Zipper Knife, which double cuts the sheeting to keep it from jamming. These zippers are tough and can be used both indoors and outdoors in freezing temperatures. • Durable, 3" wide all-cloth construction, holds up in high-traffic areas • Works in temperatures below 55⁰ F • Clean-cutting ZipperKnife™ sheeting cutter eliminates zipper jams • Flap hooks hold flap up allowing easy entry and exit