Buying weapon Mods

[OBL Apocalypse]

How do u know exactly that the weapon Mod your buying will fit your weapon?

i have bought 2 magazines and a scope and when I looked at them it listed the guns they fit and my gun was listed and even had a white square with a triangle beside which I figure means that gun is equipped.

i bought them and then went to equip them but when I scroll through the list of magazines and scopes in the Mod section for my gun I don't see them like there not  compatible with my gun..

I bought Reflex Sight-Tan from Advanced Weapon Vendor for my High End Vector 45 ACP

But I go to equip and it's not listed.. Same with the 2 Mags I bought 

Any Ideas??? 

 

[Vampiric ODST]

It'll pop up in the description of the mod. It'll say  

IE: Fits:

    Vector acp 45

   Tactical M249 para

For smaller weapo s they use small mods. The vector for example uses a silencer that a pistol would use. I'll work on getting a picture for you when I'm on next time.