A quiet SMG for night games and CQB. The built-in suppressor already keeps it hushed. The da Vinci 229mm barrel is listed for the SD5, and the Macaron bucking tightens groups. It takes the same 200 round Marui MP5 magazines. Example build by LoadoutLab. Every part is listed by its shop as made for this gun. Photo: "Tokyo Marui MP5-SD5 AEG.jpg" by Kyle Pflug (Succendo), CC BY 2.0, via Wikimedia Commons (https://commons.wikimedia.org/wiki/File:Tokyo_Marui_MP5-SD5_AEG.jpg). The photo shows this gun model; the parts list is a suggested setup.