Roelof: Can i ask why you use a replacement button with larger hole over the standard engine button? Is it to move more oil through a larger hole? If so can i ask why size hole is in the centre for both .12 button and .21? And are these engine specific fittings or fits all brand engines?

Also in a vertical position am I right in thinking no backplate or is something put in place of with an opening for oil to pass through?