Built to US military specifications for optical performance, waterproofness and durability, these are among the very best marine binoculars made. Lenses and prisms are made with Fujinons exclusive rare-earth glass formulations featuring a proprietary zirconium oxide Electron Beam Coating (EBC) process that enables them to transmit an incredible 95% of the light striking the objective lenses, a critical advantage in low light, such as at dawn and dusk.