Leica Duovid 10/15x50 are the first premium binocular to feature such switchable magnifications. This is a beast of brilliant optics, starting with great 10x intimacy and springing all the way to 15x when one has enough available light to afford the smaller exit pupil. Great for big game hunters.

High-powered binoculars are difficult to hold steady by hand; a monopod (and a tripod adapter if not included with the binocular) with an incorporated fluid pan/tilt head or with such a head attached between the monopod and the binocular is highly recommended.