or larger openings and penetrations where putties and strips alone aren't enough, use 3M™ Fire Barrier Composite Sheet CS-195+, a one-part firestop system that installers can cut and form to exact sizes - no mixing or damming required. These sheets are easily installed using common tools and fasteners. Ideal for firestopping penetrations such as cable trays and conduit, the sheets feature intumescent material bonded to 28-gauge galvanized steel, reinforced on its facing side with hexagonal wire mesh and covered in aluminum foil. This combination of organic/inorganic materials makes these composite sheets a reliable firestop in tested and listed systems, new and retrofit. These materials also make an excellent thermal conductor, helping to dispel built- up radiant heat to preserve process and control equipment and help minimize cable derating concerns. 3M™ Fire Barrier Composite Sheet CS-195+ is firestop tested up to 4 hours in accordance with ASTM E 814 (UL 1479).