The delightfully named DumpCan from Hunsaker, in basic trim with a 2-way billet vent cap and threaded billet pour cap.
Hunsaker 5-Gallon QuikFill DumpCan w/ 2.25" hose and a 1" pour spout--according to Hunsaker, works well with the OE fuel-filler necks on most cars. We don't own most cars, so have to take the guy's word for it. Also includes billet vent cap.
Hunsaker DumpCan w/ 1.25" hose and expansion-twist plug for quick storage. Also includes billet vent cap.
Besides increasing personal size and virility, can also be attached to a Hunsaker 5-Gallon DumpCan for fast fueling and quick sealing via the twist-plug cap.