Small cylindrical magnets approximately 12 x 4mm, that would have been glued to plotting counters used in Filter and Operations Rooms. Some surface corrosion but they retain excellent magnetism. Similar magnets can be seen in some of the photos shown - attached to counters and used to prevent them from falling off the sweep-raid plaque (narrow tray like strip). We have 7 available, priced individually. Stock code M26543-49.