The Hurricane 10x50 Porro Prism Binocular from Vortex features individualized eyepiece focusing to achieve the ideal focus for each eye and aid in a more secure tube sealing. The Porro prism architecture provides enhanced three-dimensional imaging, less light loss and generally sharper images. Optimized for low light conditions the Hurricane sports a 50mm objective lens for greater light transmission ability. Dawn or dusk, or overcast skies won't hinder the clarity and brightness that this glass is capable of. The Hurricane needn't fear the cyclone. O-ring seals prevent water, moisture, dust, etc. from entering inside the binocular while argon gas purging ensures no internal fogging. Rubber armoring provides a secure and comfortable grip, as well as added shock-resistance while Vortex's ArmorTek protects the exterior lenses from scratches, oil, dirt and the like. The optics have not been ignored. Vortex proprietary XR anti-reflective coatings, fully multi-coated on all air-to-glass lens surfaces, increase light transmission for maximum brightness. Windy, wet and inhospitable? Make sure that you have this binocular as a companion.