The IBM Disk Operating System DOS Version 3.20 5.25 Diskette is a vintage computer product released by IBM in the United States. It is a 5.25 diskette containing the IBM Disk Operating System DOS Version 3.20, which was commonly used in early personal computers. This item is a collector's piece for enthusiasts of vintage computing and is in its original, unmodified state. It is a valuable piece of computing history that offers a glimpse into the early days of personal computing.