This is a UP0746 Top Stop Red Polyester Stopper is a two-component chemical paste used for the filling of small holes & imperfections in surfaces prior to being over-painted. Very soft smooth paste which is easily spread in thin layers to provide the perfect finish for painting & easily sanded wet or dry after a few minutes. It can be used on the following surfaces: Bare steel, polyester body filler, original paint surfaces. Comes in a 750ml tin.