I have recently purchased a new tripod (Oben AC-1400 AL with BA-00 HEAD) and there is a round plate between the tripod and the head itself. It seems like it is meant to remain where it is but I think the head is more secure without it as it catches more thread on the screw the connects the tripod and the head.
Is the round plate necessary? what is it's purpose?
Edit: Added a model name, link and a picture showing the location of the plate.
Edit: Added a new image to show the screws on the plate and that they do not extend into any opening in the head itself.