Offering up to 3 hours of protection, 3M™ fire barrier pillows are self-contained, intumescent products designed for use in through-penetration firestops, such as cable trays, conduit and blank openings. During a fire, 3M™ fire barrier pillows intumesce (expand) and lock themselves into place, surrounding the penetrant(s) to help prevent the spread of smoke, fire and toxic gases. These fire pillows are easy to install and do not require mesh wire. They are ideal for projects requiring re-enterability of a firestop system, simply remove and replace pillows as needed. We designed this product with graphite-free composition, which does not conduct electricity. Additionally, these fire protection pillows have excellent aging properties, providing long-lasting durability and performance.