ROOF X TENDER® 983 Ultra Base Roof Primer is a water borne epoxy formulated for use with Roof X Tender silicone coating. This product is used as a primer/base coat prior to application of ROOF X TENDER® 985 Super Silicone. Application of 983 Ultra Base helps to prevent bleed through over asphalt substrates. Additionally, Ultra Base has been designed to use with Polyester Reinforcement. The addition of polyester reinforcement creates a fully adhered and seamless coating that is stronger, more versatile and 100% waterproof.