AC MMCX and OEM MMC

Hi,
Any buddy know what is difference between"AC MMCX and OEM MMCX-N " ?
they just told me that (MMCX-N doesn’t fit MikroTik enclosures) !! when I google it i get the same picture! :frowning:
and where i can find “RPSMA” for RB912UAG-5HPnD-OUT.

http://www.ebay.com/sch/i.html?_sacat=0&_nkw=rpsma+connector&_frs=1