Anti-Magic Mask

The Mask of Magic Resistance (aka Anti-Demon Mask) is a mask owned by Chloe O’Bell. It was given to Shizue Izawa to suppress Ifrit, who resided inside her. It was later passed down to Rimuru Tempest. From there, the mask would later ironically be given to a young Chloe by Rimuru.

While the real mask is currently in the possession of Chloe, Rimuru is able to duplicate a working copy of the mask complete with its ability for his own usage.

Ability
The mask has the ability to suppress magical aura.

In Episode 24, during his battle against Shizue, Diablo suspected that the mask has the ability to suppress time, this ability is known as Infinity.