The Olymberyl Aidan (HFB443) Top Flue Collar connects the flue outlet of your Hi-Flame Olymberyl Aidan to the flue pipe, sealing the junction against heat and combustion gases. This genuine spare part is made in cast iron to the original specification for the Olymberyl Aidan. A properly sealed flue collar is essential for safe stove operation and correct draught. Fitting is straightforward.