Marushin M2 Carbine version?

if by export you mean non japanese spec like my new 6mm blowback version, you will find there is no ld2 hop fitted.
to reduce power on jap spec models there is a kink in the barrel and a second fixed red hop nub at the muzzle end.
if you look down the barrel with the bolt locked back either both of these will be visiable.
if you mean export as in usa propane version ,it will be unlikely as spartan usa didnt do that many and i dont think theres any visible clues apart from there name on the box.