Replace a damaged or poorly sealing flue collar on your Hi-Flame Precision Inset (HF357i) Boiler (AL357i) with this genuine spare. The Precision Inset Boiler Flue Collar is the cast iron connector between the stove and flue pipe, and a good seal at this junction is essential for safe operation. This replacement is made to the original specification and fits the Precision Inset Boiler flue outlet directly.