A polymer edition of the G&G ARP556 AEG is in stock at Softair Zone and they walk us through its features... "Here we present you the polymer sister model of the ARP556. In contrast to the top model, it consists almost entirely of polymer.

Difference is besides the material that it is not ambidexrtrous. In the internals it is almost identical and also equipped with an E.T.U. It has undergone minimal changes, but only visually."