Transdimensional (3.5e Equipment)
From D&D Wiki
Transdimensional: A transdimensional weapon is linked to the fabric of the multiverse and likewise to the wielder's soul as if the three are sewn together by thread. The prospective wielder of such a weapon must perform a ritual that takes 24 hours in order to bond with it, once bonded, the weapon cannot be bound to anyone else unless the bonded wielder goes through the same ritual again. A transdimensional weapon can be dismissed and summoned to and from it’s own miniature pocket dimension by the bonded wielder as a free action. When the weapon is out of the bonded wielder’s hands for more than 1 hour, it automatically returns to it’s respective pocket dimension. Also, if the transdimensional weapon is ever sundered or broken, it immediately returns to it’s pocket dimension where it remains for a full week while it repairs itself, after which it can be summoned again as normal.