New, fully tested System 3.0 400K bootable 3.5-inch floppy disk suitable for use in the Macintosh 128K, 512K and Plus. This system image has been written to a new, double density floppy disk and tested on a Macintosh Plus. It will work as a startup disk on the Macintosh 128K, 512K or Plus with either a 400K or 800K floppy disk drive. If you know your Macintosh has an 800K drive, we advise buying our 800K System 3.2 disk. Brand and colour of disks may vary.
Note: Since a faulty floppy disk drive can damage a floppy disk, you should insert a dispensable disk first to make sure the drive is loading, ejecting and not making any unhealthy noises.