Posting in subject line so it is easy to find. Bear with me here. I didn't find any posts that specifically addressed this subject in TDR. I Googled:FS19856 and found a post @ cumminsforum.com. Within that post there is a link to cumminfiltration.com. The link does not work. If you go to cumminsfiltration good luck finding newsletters or product literature. I gave up. Bottom line, when you order the premium 7micron filter from Genos you used to get FS19800E. You now get FS19856_P. The new P/N is apparently the same filter media but the gasket (yellow) is ULSD compatible. The old one was not? The new gasket may be aimed at biodeisel use. I've been running B2 to B5 for year or so, have not had any leakers, and I just changed out to my last FS19800E. The FS19856 will go in next time. Best bet is to call Geno's for some background.