This is why I hate that negative Quality

Arguably, a MegaCorp makes just about every item under the sun. And some of them in multiple brands! Add in the spider's web of Controlling interests, Shell Corporations, Holding Subsidraries, and other asset management tricks, it's impossible to know unless they put a sticker on it!
And while the "Ares Predator" is obviously made by Ares, you can be that Aztech has a knockoff of it sold under a different name! And it is also unreasonable to think that the books list every possible item made by every possible production firm

(love to flip through that Sear's catalogue! probably 30 feet tall!)
So it kinda falls on either side of the same fence:
Either you can't use the item at all unless its got the company name on the sticker (as in listed in the entry or as a SUBsid of said company) <rather harsh>
Or it becomes an RP stick/tool where the player/character goes through endless searches looking for the "right brand" of heavy pistol through his contacts/RP time. But looks up and buys Ares Predator(Evo dazzler) from the book.
Depending on the table, both are acceptable.