Useful Top Hat
Hatband made of giant spider silk.
This stylish and sturdy top hat conceals a useful feature: a small pocket dimension. You may store up to 50 pounds worth of items in the extradimensional space. Retrieving an item stowed this way requires a bonus action (to remove the hat) and an action (to retrieve the item). If you have never interacted with a specific useful top hat before, the first time you use it, it requires 1d4 rounds to take stock of its contents before anything can be retrieved from the bag.
As with all extra-dimensional storage, food or drink placed inside immediately and permanently loses its nourishing qualities, and a body placed in it cannot be restored to life by resurrection , revivify , or similar magic. Living creatures cannot be placed in the space and are merely stowed as though in a mundane top hat if it is attempted. The pocket dimension cannot be accessed until the creature is removed. The hat cannot hold any item that would not fit in a normal hat of its apparent size or any item with the Bulky quality. If the hat is punctured, torn, or otherwise structurally damaged, it ruptures and is destroyed, and the contents are scattered throughout the Astral Plane.
Placing a useful top hat inside another extradimensional storage device such as a bag of holding results in planar rift that destroys both items and pulls everything within 10 feet into the Astral Plane. The rift then closes and disappears.