Armourbond Flash Self-Adhering Base Sheet Flashing is constructed of a tough non-woven reinforced polyester mat strengthened with select glass fiber strands that is coated with select SBS polymers and premium asphalt to a thickness of approximately 2.5 mm (98 mils). A thin micro-perforated film covers the top surface of the product, while the self-adhering underside is covered with a removable silicone treated release film. Armourbond Flash may be placed in flame-sensitive areas for flashing details.