This is a TRE4603 2 IN 1 Aerosol Primer. 2 IN 1 pimers are a specialty coating designed for easy & convenient priming of metal & plastic parts. These primers prevent rust & seal out moisture, while providing a smooth base for topcoat application on metal substrates. Also, has excellent flexibility & adhesion properties that enable them to be applied to flexible & rigid parts. Is fast drying, provides superior fill & build & is very easy to sand. Also compatible with virtually all automotive paints.