Set of six, 3inch diameter (9.5" circumference) stovepipe heat reclaimer / Aluminum Heat Exchanger / radiator rings that reclaim heat from the hot stove pipe and radiate the heat into the room. They make close contact with your stack / pipe to draw more heat out of the pipe. They increase the area of heat dissipation,just like the aluminum fins on a motorcycle engine. Heat is conducted into the radiator loops where the heat is transferred into the air. They are widely used as stovepipe heat exchangers that reclaim heat from the hot stove pipe and radiate the heat into the room. This offer is for one lot of 6 radiators. They are made of 28 gauge high thermal conductivity aluminum, 1 ½ inches wide. They attach quickly and easily to your pipe or exhaust stack. No screws or tools needed. They stretch to make a tight contact with the pipe. The ends lock into each other. It takes about 2 minutes to attach all six radiators. The bands conduct heat from the points of contact on the pipe to the loops in the band where the heat is released. They will last a lifetime. They never need maintenance. They are guaranteed to draw more heat from the pipe. You may put on as many bands as you have room for. One set of six bands covers 9 linear inches of exposed pipe.***PLEASE*** Confirm Circumference (measure length around with flexible tape or string)3" dia. = 9 1/2" cir3.6" dia. = 11.5 cir4" dia. = 13" cir5" dia. = 15 3/4" cir6" dia. = 19" cir7" dia. = 22" cir8" dia. = 25 1/4" cirNOTE: The length of pipe in the picture is not part of the sale.HOW MUCH FREE HEAT? (example for a set of 6" diameter bands:Each band has 10 loops that are 2" x 1.5"…that is 30 square inches of sheet metal.6 bands x 30 = 180 square inches of sheet metal. That is equivalent to a 12" x 15" sheet of steel.So in effect, by installing this set of 6 bands, you create the equivalent of a hot, 300 - 700 degree sheet of sheet metal, radiating heat from both sides of the sheet into the room before it escapes out the chimney. That is like a small space heater itself...and it is FREE HEAT.They are guaranteed to draw more heat from the stovepipe and pay for themselves in a short period of time.You may put on as many bands as you wish or have room for. The more bands, the less heat going out the chimney.They may be re-used if you replace the old stovepipe.