Pemko S88BL510 Black Silcon Smoke Seal Gasketing designed to be installed on the perimeter of a door opening to slow/prohibit the passage of smoke, fire, weather, sound and dirt. Unaffected by sunlight, ozone and ultraviolet rays and is impervious to fungus and mildew. Designed for normal frame gaps, 1/4" x 1/2" bulb seal begins compressing at 1/4" and compresses to seal up to a 1/16" gap. Compression bulb helps to absorb the door’s closing impact and requires an extremely low latching and opening force. It has an effective range between -58°F and 450°F.