The Donaldson P573481 filter appears identical in shape to the T4125-38021. Both sealing surface diameters are the same. In particular the one I was questioning before I purchased the Donaldson filter was the internal O-ring that should seal over the protruding tube of the tractor filter housing, which is does. The only visual difference, other than color, is the internal metal mesh pattern. The T4125-38021 has many small round holes where oil passes through. The Donaldson has many rectangular slits that are laid out in a spiral where oil passes through. This tells us that the internal media is different. One thing to note, these two different filters I'm comparing were purchased 2 years apart from each other. (manufacturing may or may not have changed). According to Donaldsons website, this P573481 filter has an 11 micron synthetic media, which is on par for the application. I found no information about relief pressures. I'm not certain they even have an internal relief valve at all. They may not need one, as the tractors HST has its own. Something that could be worth looking into or debating to be sure of. But having said that, there is nothing magical about the daedong HST. The Donaldson P573481 is used widely in Caterpillar machinery within similar systems of equal pressures and fluids. And the filter fits my Kioti quite nicely. I Installed the P573481 in my 2014 DK45 12 running hours ago. No abnormalities thus far. Though I still think their is value in further research. Now If we could just cross reference that T5710-38031....
