This kit comes with the correct seal that came in the JK'S new from the factory.
These are all OEM Dana Spicer parts
I don't use the National 9912 seal as the local auto parts stores do.
You will also notice the JK seal is 5/16th of an inch taller than the TJ / older 1940's thru 2006 Dana 44 axles
If you look at the last to pictures you can see the difference in the height as the seal comes through the retainer plate