The Z-Flex Z-Vent 2SVSLSF04 Storm Collar is a 4" component designed for vertical venting applications, offering a reliable weather seal when paired with adjustable roof flashing. It prevents rainwater and debris from entering the venting system, ensuring long-lasting protection. Made from high-quality stainless steel, it is ideal for use with Bosch tankless water heaters such as the Therm 940ES and AquaStar 2700ES. The Z-Vent is rated AL29-4C and approved for Category I, II, III, and IV applications, making it suitable for high-efficiency gas and oil heaters, boilers, and water heaters. Featuring a built-in fail-safe gasket and locking band, the storm collar does not require additional sealant for installation. For enhanced sealing, Z-Vent Sealant (3oz tube) can be used to ensure a tight connection between the collar and vent pipe.