I've been using the Donaldson P573481 on both of my DK45se Hst tractors for about 100 hrs each now with no troubles. You would never know the difference at this point.
I've kept my old used Kioti filter, so when I change this Donaldson out, I will cut both used filters in half, then present photos here on the forum comparing the two. They do look slightly different internally when looking into the filter, but the ratings are the same, both with an 11 micron synthetic media, rated for the higher pressure.
Both: 87x154mm Thread: M45 x 2
Both: Gasket OD: 61mm ID:54mm
All Cross References I can find for the Kioti T4125-38021:
(Mfg.) Hitachi T412538021
Donaldson P573481
Fleetguard HF35519
Baldwin BT9464
Caterpillar 518670