4" Black Hy-C Smoke Guard cures most smoking problems resulting from a flue sized too small for the fireplace opening. The smoke guard can be used to reduce the height or width of the fireplace, thus reducing the fireplace opening. It is spring-loaded, adjusts from 28 1/2" to 48", and installs without tools.
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.