This is a 48" tube-in-tube side-arm heat exchanger with 3/4" hook up for the domestic water heater side, and 1" hook up for the wood stove/boiler side. This side-arm will work on any size hot water heater, though installation piping may vary depending on water heater dimensions. The inner copper tube is rifled in order to introduce turbulence within the heat exchanger which improves heat exchange performance. The side-arm comes dry-fit/unsoldered to more easily fit your exact installation.
