4 Wall Thimble With Air Intake (1 Clearance) 2 Al Flex; (2) Hose Clamps

Allows outside fresh air for combustion through the wall thimble without having to cut a second hole into the wall. Comes with an insulation ring to reduce air infiltration where the pipe slips through the thimble. The 2" diameter flex hose is 10' in length. Clamps included. Can be used in US and Canada. Patented.