Made by Señor Osorio in Nicaragua, this is a .22 rimfire caliber machine pistol with several clever design elements. It fires from an open bolt, using a .22-round Italian magazine of indeterminate origin. It has a selective trigger, with the top firing in full automatic (sliding rearward) and the bottom firing in semiauto only (pivoting). Aside from some sharp edges on the vz61-like folding stock, it is a remarkably well built and refined little pistol!