DuraVent FasNSeal Flex 4" Stainless Steel Coupler d22.8 UL 641 Clearance Minimum 3"

UL 641 Clearance Minimum 3" clearance to combustibles Diameter 4" to 6

How many heaters can I control with my App

and your fire pit is cool

Note: Nest Lantern cannot use Reflective Fire Glass

DuraVent FasNSeal Flex 4" Stainless Steel Coupler d22.8 UL 641 Clearance Minimum 3"Made from super ferritic stainless steel. Corrosion resistant. Manufactured with a sure seal locking seam for superior strength and flexibility. The smooth inner wall provides for no output reduction, allowing for full appliance efficiency, ease of cleaning and regular maintenance. The smooth inner wall optimizes gas flow, minimizes back pressure, and facilitates condensate management. Only flexible chimney liner listed to UL 1738 standard. What's