Designed to accommodate large and small specimens, the National Optical 420-430PLL-20 Stereo Zoom Microscope makes it easy and comfortable for groups of people to share the view through the eyepieces.

Using a binocular head lets you view with both eyes open, which is not only more comfortable, but preserves true 3D stereoscopic vision with a rich depth of view. The two eyepieces are set a comfortable 45° angle, and it rotates in a full 360° circle so people standing or sitting at a table or desk can all enjoy the view without having to have everyone move to the eyepieces. Optically the microscope is outfitted with two 20x power eyepieces that, when combined with the zoom objective, provide magnifications from 20x to 80x with a stepless zoom mechanism that enables precise power selection anywhere between the minimum and maximum. Each eyepiece has its own diopter adjustment to compensate for individual eye strength and the eyepiece's interpupillary adjustment range makes it easy for all users to place their distance exactly where they need it. Finally, the eyepieces come with winged eyecups that block peripheral light; contrast and clarity are enhanced, especially in bright classroom or showroom settings.

The viewing head can be raised and lowered relative to the base for viewing flat or chunky specimens. The stage is integrated into the base to make viewing larger specimens like rocks, gems, textiles, and circuit boards easier. Upper and lower LED illuminators light the stage and independent power control allows you to have just the upper LED on, just the lower, or both. The upper LED also has its own rheostat dimmer to provide the right amount of light. Two stage plates are included: a frosted glass that passes light without the harsh glare, and a reversible white/black contrast plate that provides a stark difference between your specimen and background to enhance the view.