This is a vintage set of three (3) 5.25" floppy disks of Microsoft MS-DOS from 1986. The disks are in sleeves and are perfect for collectors or those looking to relive the nostalgia of the past. The operating system is designed for Microsoft DOS and is a great addition to any vintage computer collection. The brand is Microsoft and the type is an operating system. This item is perfect for those interested in computers/tablets and networking, specifically in the category of software and operating systems. Bag AA