Stackable Receipt/Notes Box (e.g. Ideal for Taiwan Payment Receipts)

What is it?

These are a stack-able receipt holding boxes, e.g. using 2 for different groups/types of receipts. Can of course be used for any sorts of receipts, paper notes, ... It is a successor to the previous design (https://www.thingiverse.com/thing:1751184), which is now much sturdier and has better fit for stacking. It is also compatible with the old design.

What is the reason in it?
* Improve the original design in general

* Make it sturdy, while keeping material usage low (1 box ~40g)

* Improve connection areas for easier and safer stacking

* Maintain compatibility with V1 - though looking back, that was not necessary, as simply reprinting V2 designs is an easy thing