VC-132 Noritz Stainless Steel 5" Diameter Outdoor Vent Cap The VC-132 5" vent cap is made of high temperature stainless steel to help protect your outdoor tankless water heater while providing a clean professional look. As part of the N-Vent series, this product is UL approved category III venting, known for easy installation and forming tight seals.High temperature rated stainless steelProtects vent systemUnique gasket enables tight sealEasy to install Quick-Snap connectionSuperior design