7"

Only UL listed heat reclaimer on the market. Reclaims up to 30% of otherwise lost heat going up your chimney and distributes it into your home.
Crimp down configuration is designed for use with wood burning heating applications with inside flue temperatures exceeding 350 degrees and surface temperatures of the single wall pipe below the Magic Heat exceeding 280 degrees.
Easy to install. Fits 6″ flue diameter. Built in soot scraper cleans tubes internally allowing for maximum heat transfer.