11" Lock-Top Round-Square Adaptor For Round Flue Tiles - DLTRS11
This adaptor slips inside the round flue opening, and the damper is attached to the square (top) of the adaptor. Helps your damper create a snug, secure fit to your chimney.
WARNING: Carcinogens: This product can expose you to chemicals including Lead, which is [are] known to the State of California to cause cancer. For more information go to www.P65Warnings.ca.gov.