6 Stovepipe heat Reclaimer / Radiator Rings / Bands, 6" Dia fuel efficient Collars capture heat from stove pipe. Fits approx 18.7 inch circumference ( 6 diameter stovepipe). 28 ga. steel, 1 1/2 inch wide Reclaim wasted heat from your stovepipe. Exchanges heat from your stovepipe to your room They pay for themselves in a short period of time. They will last a lifetime. They never need maintenance.