Arcane Puzzlebox

This 4-inch wide puzzle box displays complex runes which cannot be destroyed other than a disintegrate or wish. After 3 hours of consecutive uninterrupted concentration on the puzzle box to unlock it, you must roll 3 consecutive Intelligence checks, the DC of which depends on the rarity of the puzzle box:
Uncommon: DC 12, Rare: DC 14, Very Rare: DC 16, Legendary: DC 18.

If one of the three checks fail, the box 'locks' and the puzzle cannot be attempted until it resets at next dawn. A knock spell can be used on the puzzle box to reduce the number of checks required down to 2, but it cannot be reduced further.
Once opened, the puzzle box can be opened by the last person to open it by a single touch, while others need to spend the concentration required to open it like normal.
The last person to open the puzzle box and then close it also gets a mental alarm whenever someone fails an Intelligence check to open it (Provided they are on the same plane).

Each box contains an item no larger than 5 cubic feet and appears in front of the box when it is collapsed open.

Notes: Container