Pros:
easyto build
pretty sturdy
easy to use
Cons:
SOMETIMES fires two at once
occasionally ammo gets stuck in the barrel, but more bands will fix this.
Not so amazing design, you probably have seen something similar to this before.

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eg. not hard to build=easy to build
not extra likeyly to break= relatively sturdy
not difficult to operate=easy to operate.
and also, those are not even Pros themselves. they are STANDARDS. like having a true trigger is a standard, shooting is a standard, not falling apart is a standard. not difficult to operate? if it is worth posting a slide show, then it needs to work without any problems, unless they are going to be fixed.
a couple ppl wanted me to make it shoot, so i made it shoot