In Yu-Gi-Oh what is the thing that holds their cards while in battle?

In Yu-Gi-Oh, the characters don't physically hold their cards during a duel. Instead, they use a special device called a Duel Disk.

The Duel Disk is a wrist-mounted device that projects a holographic field where the cards are displayed and manipulated. It allows the players to summon monsters, activate spells and traps, and conduct the duel in a dynamic and visually engaging way.