The Flex Split Pipe Boot is factory produced from Flex's 45 Mil MF/R Elvaloy Flashing Membrane. The Flex Split Pipe Boot prefabricated pipe flashing may be used on all pipe shaped roof penetrations but was specifically designed for installation in areas where access to the top of the pipe penetration is limited or impossible. The Flex Split Pipe Boot is manufactured in sizes that allow for flashing pipe type penetrations from 1" to 12" in diameter.