Boss Products 380 Contractor's 100-Percent RTV Silicone Sealant, 10-Ounce A very versatile caulking that will adhere to many surfaces including, metal, glass, most wood, silicone, ceramics and plastic Sometimes a primer may be needed for the best adhesion to some substrates Boss 380 is authorized by the USDA for use in Federally inspected meat and poultry plants Cured sealant stays rubbery from -60F to 450F