MasterSeal NP1 10.1 Oz. Polyurethane Sealant, Black. Packaging may vary, Pack of 4. A versatile moisture-curing high-performance polyurethane sealant with permanent elasticity (Formerly: Sonolastic NP 1). For use on active, vertical and horizontal interior, exterior joints including expansion wall joints, floor and pavement joints, curtain walls, panel walls, precast walls, window frames, structural components, dams, spillways, and storm water drains. Substrates include concrete, masonry, aluminum, and wood. Bonds to concrete, masonry, and other materials without a primer. Does not require mixing. Skins overnight and fully cures within a week. Dries smooth and is paintable.