The number before the magnifying glass indicates the magnification, for example, 8X30 indicates that the magnification of the magnifying glass is 8x.
If it is a double-rate type, separate the two numbers with the / symbol. For example, 2x/4x means that the magnification of the magnifying glass is 2x, and there is an area of the magnifying glass with a magnification of 4x. If the lens is rectangular, the width of the lens is indicated by the previous number, and the height of the lens by the following number is indicated in millimeters. For example, 100X50 means that the width of the lens is 100 mm and the height is 50 mm. Like telescopes, shoddy magnifiers also like to make a fuss about magnification, and the nominal magnification is often much higher than the true magnification. In fact, the common magnification of single-lens magnifying glasses is less than 10 times, and the common magnification of double-lens magnifying glasses is less than 20 times. If magnification requirements are high, a microscope is required. Different occasions need to use different magnifications, not the higher the magnification, the better, high magnification means that the field of view is small, in some occasions the field of view is more important. (Magnifier = 250 / Lens focal length + 1, mm units)