(7 Oz Cartridge, Parts A) A medium-density, two-part silicone elastomer supplied as A and B liquid components designed for use as a fire, smoke, noxious gas and water sealant. 2001 Silicone RTV Foam is a medium-density, two-part silicone elastomer supplied as A and B liquid components designed for use as a fire, smoke, noxious gas and water sealant. 2001 Silicone RTV Foam is designed to seal large and/or complex penetrations.