Power X Obj. Dia.

Conquest HD 10x42 Binoculars

All binoculars are labeled with this pair of numbers, known as the designation. The first number signifies the power or magnification and the second signifies the diameter in millimeters of the objective lens - the lens the light enters. Full descriptive text along with how each of these will effect your view can be found in the Basics II article in the All About Optics section.