3 oz. copper asphalt laminated to a sheet of creped kraft paper reinforced with fiberglass scrim to meet government requirements. Compatible with all pressure treated lumber. Use as a flashing or termite barrier. Lightweight, flexible, conforms to any surface. Will not corrode or degrade like aluminum flashing. Looks great on sills and trim flashing applications. Chemical-free. Use asphalt based sealant to lap joints. ACQ compatible.