SEAL-ONCE NANO+POLY Premium Wood Sealer combines our proprietary nanotechnology formula with the strength of polyurethane to provide 360° of protection. The NANO creates a durable finish that allows wood to expand and contract, while the POLY adds surface protection against wear and tear in high traffic areas. Unlike many sealers that only form a top-coat, NANO+POLY penetrates below the surface to form a long-lasting, water-resistant shield around the wood fibers at the cellular level. This penetrating protection from water intrusion helps resist wood rot, decay, mold and mildew. It also stabilizes wood, eliminating warping and cupping. It is a great investment to preserve old or new wood and extend its natural life for years. When used as a wood stain, the NANO+POLY Standard Colors provides added UV protection. NANO+POLY has no toxic chemicals like many oil and solvent based sealers, so it can be applied around your home, landscaping, vegetation or over water safely. Warranted to prevent long-standing water accumulation for up to 10 years on vertical and 6 years on horizontal surfaces. Color: Clear.