Size: 25mm x 75mm x 1.1mm Package Included: 1 x microscope micrometer The method of use is as follows: 1. Pull out one side of the eyepiece from the lens barrel, unscrew the part under the eyepiece, place the micro scale on the side of the eyepiece down on the focal plane of the eyepiece, reinstall the unscrewed part back into the eyepiece, and then insert the eyepiece back into the lens barrel . 2. Place the scale on the stage side micrometer upwards and clamp it on the stage so that the scale of the side micrometer is in the center of the field of view. Adjust the focus until you can see the graduation of the micrometer on the side of the stage. 3. Carefully move the micrometer on the stage side and turn the micrometer on the eyepiece side to make the straight line on the left of the two feet coincide, and then find the straight line where the two feet overlap another time from left to right. 4. Record the number of divisions of the micrometer on the eyepiece side and the micrometer on the stage side between the two coincident lines. Calculate the actual length represented by each grid on the side of the eyepiece. The actual length represented by each grid of the eyepiece ruler = (the number of grids of the stage micrometer between two overlapping lines/the number of grids of the eyepiece micrometer between two overlapping lines)10um 5. Take off the micrometer on the side of the stage and replace the slide specimen to be measured, and measure the specimen with the micrometer on the eyepiece side.