AC Draft Shield central air conditioning vent covers winterize your home by blocking cold drafts from exiting your central AC vents. Fits grilles up to 16"L x 8"W x 2" D. CA-series covers are designed with a specifically engineered foam matrix for long term applications such as winterization and specially designed to conform to irregular surfaces forThe best draft seal possible while being gentle on walls and ceilings as to avoid marks or yellowing.