Used 1085 Sq. Ft. Mueller SS Plate Heat Exchanger, Hot side 6" flg., Cool side 8" flg. Unit has 122 plates, plate model is AT80-M, material is 304-SS, gasket material is NBR (nitrile buatine rubber) Unit is a narrow gap, wide gap is their Free Flow design. Max Pressure 150PSI@150F. Wide gap plate model number is 40N161. Built 1995. Model No. AT80B-20, S/N: 171130-1, NB# 24924.