Our 3M™ fire barrier self-socking Pillows are self-contained firestops ideal for medium to large through penetrations. Pillows feature Interlocking strips - installers can easily lock multiple Pillows together to achieve precise fill and compression with no additional support required. Intumescent fire-rated Pillows are designed to expand during a fire, locking themselves around vital components. Presenting a simpler solution to the time, cost and material challenges of fire stopping medium and large through penetration openings. Our 3M™ fire barrier self locking Pillows combine intumescent fire rated material and a range of sizes with interlocking strips that allow installers to easily lock multiple Pillows together without tools. Installers can also cut and reseal the Pillows in the field. This makes it easier to assemble ideally sized firestops for specific penetrations in floors and walls, installed to the correct compressions for maximum effectiveness in new construction or retrofit applications. No wire mesh, steel cover plates or other additional support is required. The Pillows are fully re-enterable and reusable the interlocking strips can be released by hand, making it easy to reconfigure firestop Pillows as additional services are added or relocated. These intumescent, graphite-free 3M™ fire barrier self locking Pillows are designed to expand during a fire, locking themselves into place to protect vital components and forming a tight seal against the spread of flame, smoke and toxic gasses. They are firestop tested up to 3 hr in accordance with ASTM E814 (UL 1479) and CAN/ULC-S115 when installed in listed systems. Since 1925 when one of our lab assistants invented masking tape, 3M™ has been applying science to life developing adhesive products and technologies that help entire industries and individual businesses worldwide. The work that began with a single 3M™ engineer now spans decades and generations. And all of it goes into each of our adhesives, sealants, protective coatings and firestop systems like 3M™ fire barrier self-socking Pillows to improve performance and to help businesses like yours operate faster, better and more efficiently.