The design of the second Duel Disk suggests that Seto Kaiba designed it based on memories from his past life as Priest Seto, who used the Millennium Rod.
Shimon Muran describes a Dia Dhank as a device use for calling for Duel Monster Spirits that are sealed away in Stone Tablets. Rather, the priests used the power of their Millennium Items to summon the creatures from the stone tablets.
Notice that Dia Dhanks were seen in the final season of Yu-Gi-Oh! GX, Abidos the Third (the fifth Shadow Rider) used a Dia Dhank in flashbacks Dueling his servants in episode 40.
In the vision that Yami Yugi saw in his Duel with Dartz he did not use his Dia Dhank to summon Obelisk the Tormentor.
The center of the Disk includes the Deck and Graveyard slot and Life Point counter.
The bottom part of the disk (the part that goes around an user's arm) also contains a retractable cable that could be attached to Dueling Arenas if one player opted not to use a Duel Disk.
During the Duelist Kingdom arc, Seto Kaiba developed the first generation Duel Disk prototypes as a means of countering Maximillion Pegasus' mind reading abilities.They followed Duelist Kingdom rules except for the following changes: Prior to the Battle City Tournament, Kaiba Corp developed the second generation Duel Disk, the first one to be released to the public.Issued to participants of Battle City, this Disk played the game according to the new revisions (which make it closer to the real world version).Unlike the Duel Disk, the Dia Dhank can only control up to 3 monsters at once.
In place of the Life Point counter is the Eye of Wdjat, which contains a glowing yellow meter that measures the user's Ba, as the disk measures life points.
Seto hypothesized that Pegasus needed face to face contact for his mind reading to work so as a feature of the disks, holographic projections of the cards obstruct the Duelists from seeing each other.