Heavy-duty binoculars for inclement weather Wide field of view helps ensure you won't miss a thing. Fully-multicoated optics maximize light transmission for optimum brightness. BaK-4 Porro prisms produce excellent image clarity and contrast. Protective rubber armor outer cover provides added shock and moisture protection. Waterproof and fog-proof for handling tough conditions. 10x magnification and 50-mm diameter lenses bring your subject close with a clear view.