unknown0001

I found the following site http://www.acuraautomotiveparts.org to order new valve seals from and this is what they list.

but does anybody know the difference between these:

4 12210-PT2-003 SEAL A, VALVE STEM (ARAI)
4 12210-PT2-004 SEAL A, VALVE STEM (NOK)
5 12211-PT2-003 SEAL B, VALVE STEM (ARAI)
5 12211-PT2-004 SEAL B, VALVE STEM (NOK)


Whats NOK or ARAI???

which one would be better?


thanks