The Perminator underslab vapor mat helps reduce the penetration of moisture and water vapor through the slab and into the structure. The mat also helps reduce radon gas from entering the structure. The vapor mat will not crack, puncture, snag, split, or tear easily. It is available in 15 mil and 10 mil thicknesses, and come in 200-foot rolls. W.R. Meadows Inc. 800-342-5976.