National Geographic 40x-640x Magnification Microscope with Smartphone Camera AdapterNational Geographic 40x 640x Magnification Microscope with Smartphone Camera Adapter With powerful magnification, intuitive controls, and a complete lab kit, the National Geographic 40x 640x Zoom Microscope is made for discovery. The zoom eyepiece and three rotating objective lenses let you examine specimens at a variety of magnifications from 40x to 640x. A color filter wheel enhances visibility of clear or colorless samples, and two types of