This robe seems to have depth, as if you were gazing into a portal between worlds, where vague behemoths move at the limit of your vision.

A robe of mysterious conjuration intensifies your connection to other planes, linking your mind to the distant realms from which a puissant mage can pluck servants and bind them to his will.
Three times per day, you can activate the robe and sacrifice a prepared arcane spell (or arcane spell slot) to summon one or more monsters, as if you had cast a summon monster spell of the same level as the sacrificed spell from your class spell list. The summoned monsters can act immediately.

Prerequisites: Craft Wondrous Item, summon monster V.
Cost to Create: 5,000 gp, 400 XP, 10 days.