These numbers mean 7x or 10x magnification, and 50mm lens diameter, which allows more light to enter, giving you clearer images even in low light conditions.
Look for binoculars with at least 7x magnification (such as 7×50 or 10×50 models). These numbers mean 7x or 10x magnification, and 50mm lens diameter, which allows more light to enter, giving you clearer images even in low light conditions.