Stackable Hexbox Evolution

Based on my previous implementation of Hex box. Follow my rule that joining mechanism should be integrated to the box structure.(rather than using a separate joint part)
.
This time, a "sliding" joint was employed so that the surface area for taking the tensional force increase. This would make the box more durable.
.
In additional, sliding mechanism also make the adding and removal of box easier.
.
Moreover, you can joining two or more boxes, like what I do in the photo, to