Im sorry if there are similar thread out there.
If not, anyone is welcome to use this thread to get some help.

So here is what I am having trouble with...
This bolt is sticking out of a floor of where fuel tank was.

What does this bolt do?/ What is it for??

More detail:
There are two bolts on each side of the fuel tank floor. each one of these bolts are covered by black plastic cap(nothing is attached to it)