Fits outside flue tile size from 3-1/2'' x 7-1/2'' to 5-1/2'' x 9-1/2''. Install by tightening corner screws to provide firm grip on flue tile.
Warning: This product can expose you to chemicals including creosotes, which is known to the State of California to cause cancer, and carbon monoxide, which is known to the State of California to cause birth defects or other reproductive harm.
For more information, go to www.P65Warnings.ca.gov.