The Vortex Optics Binocular Doubler multiplies the magnification of any Vortex binocular with 32mm or bigger objective lenses by a factor of 2, effectively converting them in to a part-time spotting scope.

The doubler has fully multicoated optics and a textured grip surface, and simply pushes on to the outside of the eyecup.  Without much to carry, you'll have a second option for highly magnified observing.

It helps to have a binocular tripod adapter and monopod to take full advantage of the increased power in longer glassing sessions.