HY-Guard Roof VentGuard prevents animals from entering your home through roof vents. Most roof vents are made of a plastic material with simple window type screening or no screening at all. Animals can chew through these vents to enter the attic where they can destroy wiring, cause leaks and do severe damage to your home. HY-Guard Roof VentGuards are made from heavy-duty 18 gauge expanded mesh in stainless steel or galvanized steel that animals can not chew through. To install, simply nail or screw (not included) the Roof VentGuard over the existing vent in each corner and every 6" along each side of the guard. Then, seal all punctures into the roof with outdoor grade sealant such as silicone caulk or roofing tar. Available in multiple sizes to fit a wide variety of vent applications. Made in USA.