Z-Flex Z-Vent 4" Top Support / Storm Collar. Used for vertical (through the roof) venting to make a weather seal with the adjustable roof flashing.
Z-Flex Z-Vent is rated AL29-4C and is approved for Category I (vertical only), II, III & IV applications and is designed for use with boilers, high efficiency gas and oil heaters and water heaters where cool flue gases are vented under pressure. Z-Vent contains a built-in, fail-safe gasket and locking band connection. No sealant is required.
