The Nikon 8 x 25 Prostaff Waterproof Monocular’s multicoated, aspherical eyepiece lens and BaK4 prisms deliver bright, high-resolution images under all lighting conditions. It provides a great amount of eye relief, which is especially useful for those accustomed to wearing eyeglasses. This nitrogen-filled and O-ring-sealed monocular provides you with a waterproof, fog-proof, and shockproof performance in any environment. Like other monuclars from Nikon, it too has a rubber-armoured coating. It also has a smooth central focus knob for quick adjustment of the focus range.