BASF MasterProtect H 400 (formerly enviroseal 40) is a water-based is a 40% alkylalkoxysilane penetrating sealer for concrete. It provides long-lasting protection against moisture invasion, freeze/thaw cycles, and chloride ion intrusion. MasterProtect H 400, Enviroseal 40, water repellant is environmentally friendly and is the perfect choice for traffic-bearing surfaces. MasterProtect H 400 will not alter the surface's appearance and is one-component which makes it simple to apply and saves valuable labor time. This water sealer has breathable properties that allow interior moisture to escape without damaging the seal. MasterProtect H 400, material number 51672868, can be applied to concrete, exposed aggregate, glass-fiber reinforced, precast, cast in place/precast, silica fume, stucco, brick pavers, hard burnt brick and unglazed tile. This excellent water repellant can be applied horizontally, vertically and to interiors and exteriors above grade.