ED (Extra low- dispersion) glass prevents chromatic aberration because it gives the designer of a multi-element objective lens more options to concentrate and direct the wavelengths of light more effectively, thus they can control and minimize aberrations, in particular, chromatic aberration.

SNYPEX Optics binoculars & Spotting Scopes use an apochromatic lens design that includes high density ED glass elements and the use of the very best quality coatings like dielectric, a fully multi-coated optics, phase correction coatings Back-4 on the roof prisms, with a wide field of view, generous eye relief combined with a very comfortable and functional open bridge body design that are both fog and waterproof, Nitrogen-filled, lightweight as well as strong body because of Magnesium/Alloy body. Have a close focusing distance varies from of 6.56 ft. to 4.92ft

That all joins together and produce an extremely high quality and bright image.