A product of the 1960s, the Mark I Gyrojet uses a 13mm solid fuel rocket in place of a standard cartridge. As the rocket does not need a solid chamber or extractor equipment, the entire pistol can be greatly simplified and made from lightweight materials. The pistol is fitted with adjustable front and fixed notch rear sights as well as a set of walnut grips. The left side of the frame lug is marked with the manufacturer address, model, and caliber markings with the serial number on the underside. Includes a MBAssociated Gyrojet box.