This magnetic fireplace draft blocker is used to stop unwanted cold/hot air, pollen and dust from entering you home through fireplace vent. It's made of magnetic rubber with powerful magnetism, it can be firmly attached to your metal fireplace vent and won't fall off easily. In winter, this fireplace draft stopper can effectively keep cold air out to prevent heat loss. In summer, this fireplace vent cover can be used to keep hot and humid air out. In addition, this magnetic cover also suitable for floor, wall, ceiling vents and grilles of HVAC system or RV etc. where can absorb to magnetic materials.SpecificationColor: Black BrownMaterial: Magnetic RubberOverall Size: 1016 x 101.6 x 1mm/40 x 4 x 0.04 inch (L*W*T)Packing List: 4 x Fireplace Draft StoppersAdvantage1.