TWP 100 Series is an EPA registered wood preservative which contains a unique combination of chemicals which preserve and enhance the natural warmth, beauty and integrity of new and old wood. TWP 100 Series penetrates deeply into wood without excessive surface film build, highlighting existing grain patterns with amazing clarity and warmth and is specifically designed to provide protection against the four major causes of wood degradation wood rot, water, sunlight and mildew. TWP 100 Series will not crack, peel or blister making maintenance an easy task to perform for extended wood protection.