The Fujinon Polaris 10x50 FMTR-SX Binoculars are professional-grade Porro-prism optics engineered to withstand grueling tactical, marine, and astronomical operations. This heavy-duty instrument features an elite field flattener lens system that completely irons out edge distortion, providing razor-sharp focus from the center to the absolute boundaries of the wide 6.5-degree field of view. The large 50mm objectives are treated with Fujinon's proprietary Electron Beam Coating (EBC) multi-coatings, channeling an impressive 95 percent light transmission for high-contrast viewing under the night sky or low-visibility ocean horizone. Built to strict military standards for impact resistance, the nitrogen-purged, 100% waterproof chassis features an individual-focus eyepiece ring system that isolates adjustment for each eye. Encased in a ruggedized, shock-absorbing rubber armor coating, this legendary glassing setup guarantees a slip-resistant hold in driving salt-water sprays or freezing wilderness downpours. Fujinon Polaris 10x50 FMTR-SX Water Resistant Binoculars w/ Field Flattener Lenses, Lens Multicoating, Rubber Coating 16330756