upgraded prometheus Tight bore barrel, supressor, Sight and drum mag. I paid $40 for the surpessor $80 for the sight and $86.99 for the drum mag. the supressor is the s100 by g&g sight is by aim sport a very reputable brand, its fully fuctional as all of the gun is aswell. it also has a silver(coloured, made of 6061 Al) outerbarrel compared to the stock matte black.