• 10x50 binoculars are designed as a specialized equipment for viewing distant objects or landscapes.
• 10X magnification, 50mm big multi-coated objective lens to achieve 367ft/1000yds large field of view. These excellent features allow you to broaden your horizons and enjoy watching from a distance, even when you are watching fast moving subjects.

• Hydrophobic coating: keeps snow, water, and fog from making your vision blur.  
• Anti-reflective (AR) coating: improves the transmittance of light, reduces reflection from lenses, and eliminates stray lights. Anti-radiation coating: to protect your eyes from radiation. UV coating: to protect your eyes from UV radiation. 
• Hard coating: to prevent heavy scratches from occurring on the surface of the lens. 
• Photochromic coating: to make lens darken on exposure to specific types of light, most commonly ultraviolet (UV) radiation.

Bak4 is a glass designation used by Schott AG, an old and respected German manufacturer of optical glass. BaK stands for BaritleichKron (German for "Barium Crown"). It is used for prisms in most (but not all!) high-end binoculars. It has a higher refractive index than BK7 glass (another Schott designation). This means that, if it is used under the conditions that exist in most common binoculars ("fast" objectives, low magnification) more light from the periphery of the field of view will pass through the prisms to the eyepieces; the edge of field will be brighter, but there will be no effect on the middle of the field. It is therefore deemed desirable, and BK7 has acquired an undeserved reputation for being "cheap": in fact, it is better than BaK4 for some applications (which is why it is used in some of the very best binoviewers). I had to take the BK7 photograph to the right from slightly above in order to make the grey "cutoffs" clearly visible at the bottom of the exit pupil.

• IP67 Water resistance, Fog-proof, designed to inhibit internal fogging, fit for daily use, and most outdoor environment, offering an excellent user experience.

Please do not take the binoculars to go diving.