Fuel Filler Hose Question

I have a 71 Std Bug that has the typical gas smell. I have one
question about replacing the filler hose. You have the actual hose,
the inner "Rubber band" sleeves, but why the outer cuffs at each end of
the hose. One connects it to the tank and the other just inside the
gas cap. They are on the Outside of the hose and connect with two
clamps each. What is their purpose? Why not just connect the fuel
hose directly at each end. I have not taken mine apart yet (that may
answer my question) because I like to have some Idea what I'm actually
taking apart. I'm new to the VW bug and learing fast.

Thanks in advance,
JW