AmScope 40x-640x Student Compound Microscope - LED Cordless Cordless LED Microscope with 360&deg; Rotatable Monocular Head Offering Six Widefield Magnification Powers up to 640X Sturdy Metal Framework with Disc Diaphragm Separate Coarse &amp; Fine Focus with Tension Control Wall-Power Adapter/Recharger and Three Rechargeable Batteries Included