This is a set of four floppy disks containing printer driver software for the Lexmark Optra R+, RT+, LX+, and LXI+ models. The software is compatible with Microsoft Windows XP, 2000, 98, and Vista operating systems, and requires a minimum of 500 MB hard drive space, 128 MB RAM, and a 1 GHz processor speed. The disks are in the 3.5" format and come with unlimited device usage. The software is sold as-is, with no guarantees or warranties.