Useful in colder climates for preventing freezing air from flowing back into the heat exchanger, freezing it and damaging the heaterSpecifications:• 5" Diameter Compatibility and cross reference:This item is the same as Takagi, AO Smith, American Heating part number 100112598. It is compatible with the following tankless water heaters, as shown in their manual: Marey 16L, GA16LPDP, GA16LNGDP (NOT 16L ETL which uses 3" diameter pipe) DownloadsZ-Vent SVE Series IV Installation and Maintenance Instructions, 3" to 24", Single & Double Wall Z-Vent Dimensional Specifications Alternate Item # 2ZVB05 |