Enhanced Seal for Fire PreventionEngineered for 2-inch Round 3M Fire Barrier Pass-Through Device, the 3M Fire Barrier Plug is a replacement foam plug. These foam plugs work together with the pass-through device to help prevent the spread of smoke and fire. We designed this product to enhance the seal and help the device achieve UL classified L-Rating.Recommended Applications3M Fire Barrier Plug is used with a system where typical applications include: Blank openings Metal pipe Cables Cable tray Insulated pipe Combination penetrations through concrete floor/wall Gypsum wall board assembliesEngineered to Provide ProtectionReady to work together with 2-inch Round 3M Fire Barrier Pass-Through Device, 3M Fire Barrier Plug helps this system prevent the spread of smoke and fire. Enjoy the innovative design of this product that is engineered to offer resilient results.