ATN, an established leader in the world of night vision and tactical optical designs, offers many options for the professional, military, law enforcement and discerning user of night vision devices. Their products are designed with diligence and technological advancements that have made them a world leader in providing sporting and tactical optics. Their high quality optical designs are loaded with user friendly features, and offer value and functionality that deserve recognition and merit. The Viper 1 Night Vision Monocular Goggle is a small, lightweight & comfortable NVD with excellent viewing performance. This 1X night vision monocular offers the user a both eyes open style of observation that is favored by hikers and sporting enthusiasts for its peripheral viewing advantage. The included head mount provides hands-free viewing & the NVD can be flipped up when needed. The optical and light intensifying characteristics of this monocular are quite notable; the coated 35mm F/1.0 lens provides high levels of light transmission for brilliant viewing while the 1st generation intensifier tube delivers a remarkable 40 lp/mm of resolution. Your night vision experience is enhanced even further by the automatic brightness control system which helps to compensate for dynamic lighting conditions. This is a fine optic with excellent light gathering and intensifying abilities that will surely be a go-to item in your sport optics arsenal. There are many different variables that affect the distance that one can see with a night vision device, among them the object's size, the level of details being sought from the object and the conditions of observation. Night vision devices detect much further under a full moon and clear skies than they will under a new moon and cloudy skies. Many different formulas are used to determine the statistic of maximum viewing range and this varies by manufacturer, so ultimately the generation of the intensifier tube is much more relevant than any quoted statistic when determining the maximum viewing range. All night vision devices sold by B&H have mechanisms in place to protect the intensifier tube from a sudden burst of bright light, but this does not mean that bright light doesn't damage the device. No matter what, bright light in any form is not good for the longevity and performance of image intensifier tubes. • ±5 Dioptric correction • Head mounted for hands-free operation • 4x & 8x magnification available with optional adapters • 1st Generation intensifier tube delivers 40 lp/mm of resolution