Z-Flex 2SVEPWCF0402 Z-Vent Stainless Steel Single Wall Vent Pipe 4" x 4 ft. Pipe can be cut to length. The female end of each Z-Vent component incorporates a Double Fail Safe™ self sealing gasket. Examine all components to ensure that gasket integrity has remained during shipping. Gaskets must be in proper position or flue gases could leak resulting in carbon monoxide poisoning. The installation shall be in accordance with the manufacturers installation instruction.