Brush-On Rubberized Undercoating. The Same High Quality Undercoating that Rusfre has Always Offered. But, has Now Been Rubberized to give Greater Elasticity, Flexibility, Sound Deadening, Resistance to Chipping, Cracking, Peeling, & Extended Service Life. *****Brush On and Build to Desired thickness with Repeated Applications.***** *****Comes in One Gallon Container