This scale is used to achieve spatial calibration of the video dimension analyzer (VDA-10) or other video tracking system. The stage micrometer is placed on the microscope stage, and provides a precision scale with 100 µm per division. The SM-100 is useful for calibrating dimension analysis systems using a 4x objective. The SM-100 can also be used for spatial calibration of dissection scopes (1x–10x primary magnification).