The Top Damper effectively seals in “paid” energy dollars. It mounts to the chimney top and seals with a flat rubber gasket when closed. The Top Damper is constructed of premium stainless steel and cast aluminum and won’t rust like conventional cast-iron dampers. The control mounts in the firebox for quick and easy access and defaults to the open position. Heat loss up the fireplace chimney accounts for an average of 8% of your home heating costs! The Top Damper helps prevent this heat loss. Stay warmer and save money! Doesn’t require a fire safety control (fusible link). Defaults to open position for maximum safety. The precision-engineered mechanism is easier to open and close than throat dampers. Easily accessible handle mounts inside of the fireplace. Lifetime Warranty.