Benzene filters

Hey, guys.

Wanted to change the gas filter on my car.
I noticed a part sitting directly over the filter.
it looks like a small minni pump it goes in at one end a thin pipe and at the other end out again.
The incoming line runs right next to the petrol lines and the outgoing line disappears under the tank.
There is also a compact plug on the part with two cables.
Now that I don't know what this thing is for, and it's pretty messed up because of any exchange, I'm just asking you what this part is responsible for.

Greeting Mark