https://www.acehardware.com/departments/heating-and-cooling/chimney-and-flue/furnace-and-stove-pipe/4295762
DuraVent DirectVent 4 in. D X 16 in. L Galvanized Steel Exhaust Vent Pipe Mfr# 46DVA-16AB - Ace...
Designed for appliances tested and listed for direct vent and features a fully unitized twist-lock construction. Use of sealant is optional, unless specified...