You hide a chest, and all its contents, on the Ethereal Plane. You must touch the chest and the miniature replica that serves as a material component. The chest can contain up to 12 cu. ft. of nonliving material (3'x2'x2').
While the chest remains on the Ethereal Plane, you can use an action and touch the replica to recall the chest. It appears in an unoccupied space on the ground within 5' of you. You can send the chest back to the Ethereal Plane by using an action and touching both the chest and the replica.
After 60 days, there is a cumulative 5% chance per day that the spell's effect ends. This effect ends if you cast this spell again, if the smaller replica chest is destroyed, or if you choose to end the spell. If the spell ends and the larger chest is on the Ethereal Plane, it is irretrievably lost.
an exquisite chest, 3 feet by 2 feet by 2 feet, constructed from rare materials worth at least 5,000gp, and a tiny replica made from the same materials worth at least 50gp
Verbal Component (Alternative):
Thieves and pickpockets I detest, I conjure forth my secret chest.