As clifftall said.
I have a 2000 Adventurer 35U and you can fill the tank directly from this portal in addition to the filling station on the opposit side. I typically use this side as my hose on my house is the same side as the entry door.
Les (RVM12), Bonnie, Morgan and 4 leggers Bella & Bruce
2010 Forest River Cardinal 3450RL 40' Full Body Paint- 2015 Ram 3500 Laramie 6.7 ltr Turbo Diesel, 68RFE Trans. 4x4 SRW SB Pullrite 2900 18K FMCA-420438 Good Sam