TWR0004 is a downflow radiator for the Western Star 4900, model years 2009 to 2014.
The core measures 43.9375" high by 39.5" wide, 2.25" deep. It has a 2.5" inlet at the top right and a 2.5" outlet at the bottom right. There is no integral oil cooler and no filler neck.
It replaces 34 OEM and aftermarket numbers, among them WES90, 0524789000, 0524789001. 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.
