B&P Lamp 2 5/8" X 8 1/2" Chimney, 3/4 Frost 2 5/8 inch fitter by 8 1/2 inch height with a 3 5/8 inch bulge Fits Rayo and Central Draft burners All glass chimneys will vary in thickness due to the manufacturing process. They will fit the holder/burner specified in their description.