What you write about jerrycan. You can fill with petrol or diesel, and even E10. Whether there are now exactly 20L or more or less I have not measured. Fact is, you can fill the canister. Closed nothing goes out even if it is and it also occurs from no smell.
1 star less there because of not holding "yellow" filler plastic very close, and you should therefore wrap a towel therefore when filling, so that nothing drips on the ground.