Turn the knob to move the laser module up and down. When the red and blue light spots coincide, the focus is successfully set.
Note: If you turn the knob clockwise, the laser module will move up, and the red light spot will move toward the left. If you turn the knob counterclockwise, the laser module will move down, and the red light spot will move toward the right.
Note: When the bottom of the laser module reaches the highest point, stop turning the knob up.