With an objective lens with a magnification of 40X or more, the distance between the sample and the tip of the lens becomes narrower, but this device limits the approximate focus position to facilitate sample replacement.
Limiting the focus position
If the knob is rotated, the position of the stopper that restricts the upper and lower limits of the stage will move up and down.
Vertical movement stopper position is higher: counterclockwise
Vertical movement stopper position is lower: clockwise