Designed and built to achieve a supreme optical quality, the konus emperor 10x42 wp/wa will leave you breathless with the impeccable brightness and clarity of their special bak-4 prisms with phase correction. this is an advanced coating technique that will force the light beams back into phase, thus improving the image definition and contrast and creating a sharper view, especially noticeable when observing fine details. the other features of the emperor binoculars are: waterproof and nitrogen purged body, wide angle eyepieces, extra long eye relief and twist up eyecups, along with an attractive and edgy design.