Nikon's "ATB" designation in its binocular line stands for "All Terrain Binocular." These binoculars are designated as such because they are waterproof, fog-proof and shockproof by design.
All of Nikon's Monarch series binoculars use the ATB designation in addition to a few other models. The original Monarch ATB was perhaps Nikon's most popular and best-selling model worldwide. As of 2014, Nikon had discontinued this model, replacing it with the newer Monarch 3, 5, 7 and X models.
Nikon was founded in 1917 as Nippon Kogaku K. K. The Victor, or Tenyu, model was the first binocular model ever sold by Nippon, starting in 1918. It was actually built by Fuji Optical Works. The first binocular made exclusively by Nikon was the Mikron Compact Binocular, which began production in 1921. Nikon also produced all the camera lenses for Canon until 1947 under the name Nikkor. Nikon began producing its own cameras under the Nikon name in 1948.