The National Optical & Scientific Instruments Model 420T-420AHF-10 Stereoscopic Microscope provides the user with a large image which remains clear throughout the 10-40x magnification. In addition, the microscope shows an upright, unreversed three dimensional view and a top light with a directional beam. Optional eyepieces and auxiliary objectives can be used to expand the magnification range and working distances.

The trinocular port accepts video or SLR adapters (included), while the paired widefield 10x eyepieces are inclined at a 45° angle. The viewing head also rotates 360° for sharing with other students or colleagues. The 420T-420AHF-10's lenses are achromatic and color corrected. When it comes to focusing, large dual focusing knobs help the user to make easy adjustments. The slip clutch prevents damage from over turning, while a tension adjustment eliminates focus drift.

The microscope is illuminated by both halogen and fluorescent light. The top light being a 12V halogen with a directional beam and rheostat control, the bottom being a 110V fluorescent. Base mounted controls make operation simple. The lights illuminate two frosted glass stage plates.