RS adaptor USED TO ATTACH "THE TOP" TO ROUND FLUES

This is simply slipped inside the round flue opening and the damper is attached to the square (top) of the adaptor. For all round flues up to 8" in diameter use a 8" x 8" lock top damper.
For all round flues between 8" and 12" in diameter use a 13" x 13" lock top damper.