Enjoy a smooth zoom on the Essentials 10-30x50mm Porro Prism Binoculars, giving the variable power you need for different scenarios. A lever near the right eyecup lets you control magnification, and a center wheel controls focus. They also feature BK7 Porro prisms and coated optics. The rubber eyecups fold down for use eyeglasses, and they can be used in conjunction with a tripod with an optional adapter.