If that is what I think I am seeing, that is the original factory cart fill ball?
Be aware that that ball does not achieve a 100% seal. The 100% seal is reached ONLY after the cart label is applied over the top of the cart. Have you noticed just how tough that label is to remove??? That is what is actually completing the seal. It is not the ball.
It is a combination of the ball plus the label.
Joe
The ball material is a little soft and springy. The hole material is identical. I did not notice leakage. I have been using this design for many years. I have no problems.
Be careful, with some Canon MG printers, there is no gap, or few, above the cartridges, as you can see with my MG5150 printer.
So only low profil silicon plugs can be used !