Wondrous Item, Rare
This large, obsidian key has a two digit number embossed in gold on its handle (DM’s choice.) When laid flat on the user’s palm, the key will create a small door to a demiplane. The door measures 2ft wide by 6ft tall. The space inside measures 5ft wide by 5ft long, and 10ft tall.
Any items left inside the space remain there until the space is accessed once more. This key can only access the space it is attached to, and no others. A breathing creature within a closed storage closet can survive for up to 10 minutes, after which time it begins to suffocate.