Duda EnergyHX1220:HB12 B3-12A 20 Plate Stainless Steel Heat Exchanger with 1/2" Hose Barb Ports Copper Brazed, 2" Height, 2.9" Width, 7.5" Length

Using this in my homemade camper van to convert engine coolant heat into heated water for camping.With a 5gal flow pump this little guy heats my 21gal water tank to 110° in about 5 minNote* the picture doesn't match the description exactly, but I got exactly what the description says (the hose fittings)

I am very pleased with the heat exchanger and highly recommend this unite.The quality is very good and comes as advertised.Fast service as well.