The numbers on a rifle scope, such as 8x20, indicate the magnification power and objective lens diameter. The first number (8 in this example) represents the magnification power, meaning the scope magnifies the image 8 times. The second number (2 denotes the diameter of the objective lens in millimeters.
https://www.foreseenoptics.com/rifle-scopes
A rangefinding telescope is a device used to determine the distance to a specified target. It's difficult for the human eye to judge distances accurately, so the basic technology of telescopes is very helpful for outdoor enthusiasts or golfers. With portability in mind, you'll find that telescope manufacturers are gradually reducing the size of their models.
https://www.foreseenoptics.com/rangefinder
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