The penetrating formulation of Duro-Nox LS provides permanent hardening and sealing protection. Concrete floors treated with the product are protected from wear, abrasion, and the absorption of dirt, oil, grease, and other contaminants, making them easier to clean and maintain. The integral shine increases with use, providing a continual, long-lasting sheen. Nox-Crete Products Group. 800-669-2738.