3M FB-369 Large Fire Barrier Pillow 3-Inch x 6-Inch x 9-Inch

3M™ Fire Barrier Pillows are self-contained, intumescent products designed for use in through-penetration firestops, providing up to 3 hours of protection. This fire barrier pillow expands to form a hard char that tightly seals against flame spread, smoke and toxic gases. We also engineered this product to be re-enterable and re-useable for new or retrofit installations.