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. Fixed blade front and fixed notch rear sights, front-mounted hammer, "MARK I" marked on the left side, and a pair of smooth grips. With a hardwood MBA display case, ten dummy rounds, and 17 live rounds of Gyrojet ammunition as well as a MBA certificate of authenticity.