This remix has a thicker and taller grip with a string loop so this cap and the screw on cap can be tied to the gas can. (Much easier to find them if tethered to the gas can) 

I printed the model with the grip on the bed plus supports, I was able to get a smooth finish where the model sits on the rubber of the spout for a better seal. (printed upside down, like in the 3mf model).

I did this for my son, he lost a cap at work, so I modified one and he can now replace the one he lost.  I did print the replacement in a light blue glitter filament....  Very nice on a construction site and I'm guessing the last time they ask him for a replacement.

Like Josh's recommendation I also used PETG Filament. 

The original belongs to Josh.