Most of the newer stuff is designed and made by Donaldson. Not sure about yours but my L3940 inner and outer air are identical to the Exmark zero turn mower I just bought but half the price from Exmark or Kohler.
Donaldson P53562
eCatalog - P535362
Cross References
AMERICAN PARTS 94496 BALDWIN PA3476 BIG A 94496 BOBCAT-MELROE 6682494 CARQUEST 88496 CASE-IH CNH GLOBAL 200045A COOPERS AEM2634 FLEETGUARD AF4939 FLEETRITE AFR84939 FRAM CA7088
Kubota prices are stupid.
Regards, Fred