Our flagship product is our Insulated Magnetic Register Cover...the cover that started it all! Made of durable ABS plastic, they magnetically adhere to steel and aluminum registers alike. These covers can be used not only to add energy efficiency to your home, but also as an air diverter for rooms used less frequently. These insulated covers are a dual threat to heat loss, blocking cold drafts from coming though, while keeping your existing heat in where it belongs.