TE is right this is a vac seal tupperware lid. It comes apart so you can run your screw to the base and then just snap your cover back on. That way you see no screw but can get to it any time you need it. Also don't paint it white! It comes clear, paint the base black this will give the clear top a milky grey color. This is the screen accurate way to do it. Look at all the photos from a new hope. If you compare the white of the end caps to the dish it is clearly not white. Also the base is painted black in the film as well.