FeaturesFirestop tested for up to 3 hours of protection in accordance with ASTM E 814 (UL 1479)Expands to form a hard char that tightly seals against flame spread, smoke and toxic gasesRe-enterable and re-useable for new or retrofit installationsGraphite-free composition does not conduct electricityNo wire mesh required and easy to install, inspect, remove and reuse as neededExcellent aging properties for long-lasting durability and performance3M™ fire barrier pillows are self-contained, intumescent products designed for use in through-penetration firestops, providing up to 3 hours of protectionThis fire barrier pillow expands to form a hard char that tightly seals against flame spread, smoke and toxic gasesWe also engineered this product to be re-enterable and re-useable for new or retrofit installations