The Resisto(TM) Flex Plastic Cement is a mastic composed of bitumen, fast-evaporating solvent, cellulosic fibers (asbestos free), polymers and mineral fillers. It is used for caulking and repairing holes and cracks. It adheres to most materials without primer. Its formulation offers a great resistance to extreme temperature variations while maintaining its flexibility. Used for caulking of doors/windows and repairing holes and cracks for roofs. Good resistance to extreme temperature variation can be applied to damp surfaces, all season.