Calibration Slide for Micrometer Six Graduated Scales 1MM, 0.1MM, 0.01MM, 0.1 Inch，0.01 Inch，0.001 Inch

I needed a way to measure the width of lines and size of dots made with a laser engraver. Pop this slide over a test sample and put under magnification and there you go. It's got Milimeter and Inch scales. Under a microscope when using the smallest gradations I have to focus on the part measured and then focus on the scale as the slide is thick enough that it's outside my field of vision. Not the slides fault. Just the way my microscope works. All in all this thing is great.