The 2nd largest DBEM format, 12 in (300 mm) disks were used almost exclusively in industrial, government, medical, and enterprise archiving, where huge volumes of records needed to be stored permanently. They were most often ablative WORM, with capacities typically under a few dozen gigabytes. Drives were large and expensive, and media was usually handled through high-capacity disk changers. Few of these systems remain, and documentation is especially scarce.

To date, the only reference to be found about this disk comes from a posting on Mercari Japan¹⁾. I purchased this item in September 2026 and received it in mid-October.