This is a design that you can scale up to any size as long as you change both the length and width with the same multiplication.  The height doesn't really matter if it is changed differently.  you also have to change ALL of the pieces with same multiplication on each dimension or else it will not fit together. This would be good for an escape room or just for storing a note in a small safe.  I have not added any numbers or letters to the sides but those you can do those by yourself to create your own passcode instead of using one that I would have created for you.