A quick overview of the Sijun SJ MK18 Gel Ball Blaster by the Gel Ball Blaster Master. The SIJUN MK18 Gel Blaster boasts a solid metal gearbox with a split type design. It features functional blowback and bolt catch actions. It also includes a metal charging handle and other small parts. It offers a shooting speed of 260-270fps, which can be increased to over 300fps with a simple spring replacement (1.3mm or m95). The shooting distance ranges from 20-25 meters.