This circlet bears a tiny gem, which appears to have a hollow cage deep within its facets.

A mindvault offers its wearer temporary shelter from effects that would influence his mind. When you activate a mindvault, your consciousness is transferred into the gem held in the circlet for 1 round. While this effect lasts, you are immune to mind-affecting spells and abilities. However, you are dazed in that round as well. You can activate a mindvault after you learn the result of an incoming mind-affecting spell, but before the effect is applied. For example, after failing your Will save and learning that an enemy wizard has affected you with dominate person, you could activate your mindvault before the domination takes effect (thus negating it entirely).
A mindvault functions once per day.
You must wear a mindvault for 24 hours before you can access its abilities. If it is taken off, it becomes inactive until worn for an additional 24 hours.

Prerequisites: Craft Wondrous Item, magic jar.
Cost to Create: 4,000 gp, 320 XP, 8 days.