This is a replacement combustion air system wall thimble for DuraVent PelletVent Pro 3″ venting with a painted black exterior.
This wall thimble measures 9″ x 14 3/4″ and will fit wall depths from 4″ to 6 1/2″ and includes an insulation ring to reduce air infiltration where the pipe slides through the thimble.
Combustion Air System is a patent-pending design that pre-heats combustion air. Inbound air is circulated through baffles around the heated areas of the wall thimble pre-warming the combustion air before it is delivered to your stove