HS 340 is a premium, high performance, single-component silane, acrylic 30% solids, low VOC (400 g/l), sealer designed for SureCrete overlays or other cement-based products. As with most acrylics it is vapor permeable and readily applies outside. However, HS 340 is specially formulated for extreme climates where a low VOC sealer is required. The unique silane formulation creates the nano-sealer technology that deeply penetrates and reacts internally with cement, slowing moisture migration and efflorescence and intensifying bond capacity. Even in warmer climates HS 340s slower evaporating solvents will not âcotton candyâ before the applicator can finish a tight, smooth surface. A single coat application will provide a UV shield, enhance the beauty, and protect the surface of driveways, garage floors, patios, walkways, pool decks, and stucco.