The additional_addons.zip file you have requested: Shadow of Chernobyl / Mods / Weapons / Additional Add-ons Mod - 649.81kb is not available. Perhaps try browsing all files for the game S.T.A.L.K.E.R. Shadow of Chernobyl and upload any files you want to share or are missing. This is the only information we could locate:
This mod gives the player the ablility to add scopes, grenade launchers, and silencers to almost all the weapons in the game.