Innovative Upgrade to our Foam Vent Covers. The new design includes protection against rodents and replaces in seconds. This vent can be used on most standard opening sizes (8" X 16") and easily trimmed. The mesh can be replaced with the appropiate hooks and is able to be stacked if needed. This vent cover can be used to seal a crawl space, or the cut-outs can be popped out for venting. These allow up to 60 square inches of ventilation.