The numbers for binoculars provide important information about the specifications of the pair. Binoculars are typically labeled with two numbers, such as 8x25 or 10x30. The first number indicates the magnification level, while the second refers to the diameter of the objective lens (larger lens) in millimeters. Here’s what you need to know: First Number (Magnification): The first number indicates the magnification factor. For example, in the 8x25, the “8” indicates that the binoculars magnify the viewing image eight times its original size. This means the object will appear eight times closer than it would with the naked eye. Second Number (Objective Lens Size): The second number represents the diameter of the larger lens at the front of the binocular in millimeters. In the 8x25 example, the “25” means that the objective lens has a diameter of 25mm. The size of the objective lens affects how much light the binoculars can gather. This is particularly important in the realm of hiking binoculars because if you choose a smaller binocular to fit in your pack, you are at the same time limiting low-light performance and brightness.