Gas tank filler neck

[redhoss02]

I am trying to figure something out. I have the gas tank that sits behind the seat. The tank itself has the pipe spout coming off the side to penetrate the cab. If I remember correctly there is a hose that clamps the that and them to another piece that actually penetrates the cab through the grommet and the gas cap fastens to that. Problem is I don't know what that piece is called and have no clue where to look. Thanks guys.