Z-Flex Z-Vent 3" Extreme Weather Rain Cap Stainless Steel Venting (2SVSHRC03) 3" Extreme Weather Rain Cap Stainless Steel Venting prevents rain water from running down into your 3" stainless steel venting Designed for use where cool flue gases are vented under pressure Rated AL29-4C and is approved for Category I (vertical only), II, III & IV applications