The 3M™ Fire Barrier Cast-in Device for Metal Pipes 4MCID is an intumescent device that firestops 4-inch (101.6 mm) metallic penetrations through fire-rated concrete floor assemblies. The device is installed by attaching directly to the form before a concrete slab is poured. The 3M™ Fire Barrier Cast-in Device for Metal Pipes 4MCID creates an opening through which mechanical, electrical or plumbing penetrants can be routed after the slab is cured and forms are removed. Provides up to 3-hour fire protection. The device is installed prior to the concrete pour creating a firestop sleeve through which a 4" penetrant (e.g. metal pipe) may be passed. It helps prevent the spread of fire, smoke and noxious gas through the penetration opening. 3M™ Fire Barrier Cast-In Devices can be used with the following accessories: 3M™ Fire Barrier Cast-In Metal Deck Adaptor to accommodate fluted metal decks, 3M™ Fire Barrier Cast-In Device Height Adaptor to accommodate up to 12 in. (304.8 mm) concrete thickness, 3M™ Fire Barrier Cast-In Aerator Adaptor for aerator systems (use only with 4 in. 3M™ Fire Barrier Cast-In Devices), and 3M™ Fire Barrier Cast-In Tub Box Assembly to create a void for plumbing access (for use only with 2 inch metallic (50.8 mm) 3M™ Fire Barrier Cast-In Devices).