Pentax PTX65793 16 X 50 XCF Series Binoculars Multi-coated Lenses Provide Optimal Resolution Rubber-armored To Protect The Optics & Mechanical Systems; Pentax 16 X 50 Xcf Series Binoculars Full-body rubber housing effectively protects the internal mechanisms and optical elements Super-Multi-Coating eliminates harmful ultraviolet rays The diopter adjustment allows near- and far-sighted viewers to easily and quickly adjust the image to match their eyesight BaK-4 prisms transmit more light at the edges to enhance illumination Protected by a limited lifetime warranty