Offered only by Hammacher Schlemmer, these powerful 144X magnification binoculars can see the flick of a deer's ear 500 yards away. They can easily zoom from 20X to their maximum 144X with a simple press of a lever, providing sharp, clear images. Expertly collimated to provide a single image, they use powerful, fully coated optics, including 80mm objective lenses that offer superior light-gathering performance. They use a BK7 porro prism system, providing a field of view of 120' at 1,000 yards at 20X. With an eye relief of 12 mm and a 4 mm exit pupil at 20X. Lightweight and easy to grip with a rubberized surface; a tripod (sold separately) is recommended for stability at maximum zoom. Sturdy ABS construction. Includes carrying case and lens caps. 15 1/4" L x 8 3/4" W x 3 3/4" D. (4 lbs.)