MADE IN U.S.A. The Battic Door Whole House Attic Fan Ceiling Shutter Seal is an energy-saving insulating cover for Whole House Attic Fans. It reduces air-leakage through the whole house attic fan saving the homeowner heating and cooling loss and energy costs. The Battic Door Whole House Attic Fan Shutter Seal is installed over the ceiling shutter from the house side in the fall and removed in the spring. Attic access is not required! Simple to install – just velcro the cover into place. By reducing the amount of heat and moisture leaking into your attic, the severity of ice dams and attic mold is greatly reduced! Fits max 36″ x 48″ whole house attic fan ceiling shutters. Kit includes durable, attractive, non-toxic, white-colored, space-age foam, only ¼” thick, yet has an R-value of R-8. The foam air seals and insulates the attic fan, stopping heating and cooling loss and air leaks. The insulation is a Class A/Class 1 fire rated foam with superior thermal performance. No fiberglass – no itching. Larger kits for 48×48″ are larger also available. We use white Velcro to seal the kit. We do not use magnets. Magnets are more expensive, can be weaker, and most shutters are aluminum.