This Flue Support Bracket Helps Reinforce 90mm To 200mm Flue Systems To The Wall, Providing Peace Of Mind With Less Risk Of Unwanted Bends Within The Heating System. Providing A Secure Flue System Expels All Fumes As Quickly As Possible To Promote Heating Efficiency, Leading To Lower Fuel Bills. Designed Specifically For External Use And Designed To Fit External Flue Systems.