So it's for setting the bowl screen/ccd there are three positions, small bowl, medium bowl and large bowl - 0.1g, 0.15g, or 0.2g, if you want the large 0.2g bowl you just push it right down, but to set the bowl screen/CCD on the smaller bowls, the 0.1g and 0.15g, you fit the disc to the one of...