For Caulking And Sealing Window And Door Frames, Moldings, Baseboards, Pipes, Butt Joints, Corner Joints, Siding And Trim Crown Molding, Other Gaps And Openings. Permanently Flexible, Weatherproof And Mildew Resistant. Adheres To Wood, Aluminum, Vinyl, Plaster And Drywall, Painted Surfaces, Metal, Glass, Masonry, Stucco, Brick, Concrete, Most Plastics, And Stone. Excellent Adhesion, Paintable. Meets ASTM Specifications C-920, Class 25 And Federal Specifications TT-S-00230C, Type II, Class A.