TWR0010 is a downflow radiator for the Western Star 4900, model year 2010.
The core measures 37.5" high by 41.75" wide, 2.25" deep. It has a 2.5" inlet at the top right and a 2.5" outlet at the bottom left. The unit carries an oil cooler at the bottom and no filler neck.
It replaces 28 OEM and aftermarket numbers, among them WES17, 0529622003, 1A0208180003. 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.