The Barska 7x - 45x Trinocular Stereo Microscope Zoom allows the user to zoom or change magnification continuously throughout its magnification range providing a low to high power rang. For example, the 7x ~ 45x microscope has the ability to magnify the object 7 to 45 times higher than an unaided eye.
This stereo models feature an adjustment for interpupiliary distance (IPD) which is the distance between the viewer's eyes, interpupiliary distance (IPD). A young child will have a small IPD while an adult will have a larger one. The eyepiece lenses will spread apart or get closer to fit each individual's eyes. The adjustable interpupiliary distance is between 55mm ~ 75mm.