Chicago blower design 1910, size 3612-3650, model cb 3650 dwdi. Stainless steel wheel & shaft fan in fiberglass housing. No motor. Arrangement 3. Class 5 design. Fan rotors are stainless steel. Shaft is uhb119 steel. Center diameter is 4.72" and bearing diameter is 3.1". Performance curve on file. HP at above operating point would be 304. RPM is 2000. No motor included. Airfoil design - 1910a dw model cv 3650 di at 110% width, double inlet. Top horizontal discharge. One unit is cwth & the other is ccwth. Units are in excellent condtion.