To fit DIN51 type threads, standard for most 15 liters and 10 liter containers; please consult diagram included in the images to check for fit. 

Heavy-duty screw in plastic fill funnel 3D printed in PLA+ for 15 liter containers if you are not sure if it will fit your container, it should measure approximately 50 mm across (roughly 2")

I got fed up with trying to hold a funnel while decanting into/filling my 15 liter containers, I also didn't appreciate how slow and splashy they were, so I designed this hands-free screw in funnel with a large opening and an air return pipe to make fast splash free filling. Tough and durable. 

If you would like a spout for the same type of container, you can find it here: https://www.ebay.co.uk/itm/275622503518