Grace 4" x 75' Vycor Plus provides premium exterior protection against water, air and moisture leaks. It works by sealing a wall's vulnerable spots, such as window and door openings, corner boards, under stucco finishes, masonry walls, decks and other flashing areas. It is designed to work in severe winter climates, milder climates and in coastal areas where wind-driven rain is common. Vycor Plus is compatible with wood, plywood, concrete and masonry, it fully adheres to the substrate to prevent water from passing through. The product is 25 mil thick and available in 75-foot rolls in widths of 4, 6, 9 and 12 inches. It should not be used on roofs.