Detex 12 Steel Heat Reclaimer/Radiators for 6 inch Dia. Wood Stove Pipe. Flue/Stack Exchanger Set of six Heat Extractors for standard 6 inch diameter stove pipe. (Approximately 19 inch circumference) Wrap-around and latch...Install in less than 5 minutes. No need to remove the pipe. Reclaim wasted heat going out the stack Stove Pipe heat exchangers release free heat into your room Made in the USA from American Steel