TWP 1500 is a semi-transparent oil-based wood stain and preservative that is allowed in all 50 states. TWP 1500 Series is an EPA registered wood preservative which prevents structural damage and wood decay on exterior above ground wood surfaces such as fencing, decking, wood siding, log homes and roofing. TWP 1500 Series resists water absorption that causes warping, cracking and splitting as well as preventing freeze damage in colder climates. TWP 1500 Series is a low VOC preservative with special U.V. absorbing pigments that prevent unsightly wood graying, darkening and fading. The selected mildewcides inhibit the growth of mold and mildew which assist in preventing premature discoloration. TWP 1500 Series will keep your wood beautiful, fresh and looking new longer. The ease of application and maintenance will allow you to enjoy your investment for years to come.