Black Innerpanel Rustproofing. Chemically Formulated Rustproofing that Creeps & Penetrates into Cracks & Close Fitting Areas. Sets Up Quickly with No Lingering Odors. Sprays & Fogs Evenly. Does Not Affect Electrical Systems or Door and Window Mechanisms. Sprays on using Rusfre BB-series guns (sold separately). Comes in One Gallon Container.