Product DescriptionRugged Waterproof, Fog proof Construction. Bright, Multicoated Optics. Long Eye Relief for Eyeglass Wearers. Rubber Armored. Multi-Click Turn-and-Slide Eyecups. BaK4 High Index Prisms.From the Manufacturer The Monarch ATB 42mm with Dielectric High-Reflective Multilayer Prism Coating binocular features brighter, sharper colors, crisp and drastically improved low-light performance. A new body style provides unparalleled strength and ruggedness in a package that is comfortable to carry all day. With rugged rubber armor for added durability and a firm grip even in the worst conditions, Nikon guarantees every ATB to be 100% waterproof and fogproof, each is backed by Nikon's 25 Year Limited Warranty and No-Fault Repair/Replacement Policy. The new Monarch ATB 42mm with Dielectric High-Reflective Multilayer Prism Coating binocular is available in 8x42, 10x42 and 12x42. It is also available in Team REALTREE models with the REALTREE APG HD camouflage pattern. Technical Specs Additional Action EX Highlights:BaK 4 High Index Roof Prisms Tripod adaptableLong eye relief for eyeglass wearers Warranty Information Nikon is dedicated to quality, performance and total customer satisfaction. If your Nikon binocular, Spotting Scope or Fieldscope requires service or repair not covered by our 25 Year Limited Warranty, Nikon will repair or replace it (even it was your fault) for just $10, plus return shipping and handling. Excludes - StabilEyes, Laser Rangefinders and Spotting Scope/Fieldscope eyepieces. FAQ's Real field of view Real field of view is the angle of the visible field, seen without moving the binoculars, measured from the central point of the objective lens. The larger the value is, the wider the viewfield available. For example, binoculars with a wider field of view are advantageous for locating fast-moving wild birds within the viewfield. This also applies for finding small nebulas or a cluster of stars in astronomical observations. Apparent field of view Apparent field of view is the angle of the magnified field when you look through binoculars. The larger the apparent field of view is, the wider the field of view you can see even at high magnifications. With the conventional method used previously, the apparent field of view was calculated by multiplying the real field of view by the binocular magnification. (With this formula, apparent field of view wider than 65? is called wide field of view.) After revision, Nikon's figures are now based on the ISO 14132-1:2002 standard, and obtained by the following formula: tan ?' = ? x tan ? Apparent field of view: 2?' Real field of view: 2? Magnification: ? (With this formula, apparent field of view wider than 60° is called wide field of view.) For example, the apparent field of view of 8x binoculars with an 7.0°real field of view is as follows: 2?' = 2 x tan(r x tan ?)= 2 x tan(8 x tan 3.5) = 52.1° Relative Brightness Relative brightness value is obtained by squaring the diameter of the exit pupil. The greater the relative brightness is, the brighter the image will be. With 8x42 binoculars, the brightness is (42÷8)2= 28.1. This means that if the magnification is the same, the larger the effective diameter of the objective lens, the brighter the image will be. Do binoculars with the same exit pupil offer the same brightness?No. Brightness may vary even if the exit pupil is the same. This is because the amount of light reaching the viewer's eyes varies according to the number of lens elements and quality of lens/prism coatings. Superior optical design and highquality coating greatly contribute to the brightness of binoculars. Brightness values specified in product brochures, etc. are theoretical ones calculated in the design process. Please note these factors when comparing actual brightness values. Prisms Prisms are what let you see a correctly oriented image when you look through a pair of binoculars