M-D Building Products 68510 1/4-Inch by 1/2-Inch - 20-Feet WS108 Silicone Smoke Seal Casketing, Brown Product is listed and labeled for use on UL fire rated door assemblies Successfully tested for smoke and draft control in accordance with ASTM E-283 and SDI 116 Remains flexible from 110 degrees F to 400 degrees F Not affected by mildew, fungus or UV light U.L. listed and tested to limit air and smoke infiltration.