UNUSED 25 Sq Ft Carbone Polybloc, Cylindrical Carbon Block Heat Exchanger rated 100 PSI @ 350 deg F. 15.25" ID x 17" Straight Side. (32" OAL). Nozzles: (2) 3", (2) 4". 2 Lifting lugs. Built by Carbone of America, 2004, Model: PB13-4THU. S/N: 12455, NB # 2227.