Watco Exterior wood is a unique penetrating oil that hardens in the wood, not on the wood. New, old or pressure-treated wood becomes water-repellent, provides UV and mildew protection and resists warping and swelling caused by changes in weather.Stain, seals and protects in one easy stepWill not crack, chip or peelDurable and easy to usePenetrates deeplyExcellent outdoor protection