TFR0021 is a crossflow radiator for the Freightliner Classic XL, FLD120/132, FLT, model years 1992 to 2005.
The core measures 37" high by 32.25" wide, 2.25" deep. It has a 2.5" inlet at the left and a 3" outlet at the right. There is no integral oil cooler and no filler neck.
It replaces 107 OEM and aftermarket numbers, among them 1050082, 16333001, 1A000002. Searching any one of them will find this part.
On radiators the inlet and outlet positions, and whether the unit carries an oil cooler, decide interchangeability more often than core size does. Two radiators with identical cores are frequently not interchangeable.