Cans of improved / Public goods

This is a modified design for cans, the highlight
is the sum of the two cans to compact stack.
Ordinary cans can not be stacked up and down
a very compact,
with this design,it can be used by each of the cans
to be assembled.You can base blocks, and even
cans side wall construction,housing and so on.
You will consciously to collect these waste cans,
will not be thrown away, so that environmental, low carbon.