The PCT120 is a versatile upgrade for B120, T120, and M620 compound microscopes. It provides all of the tools necessary for use with phase contrast and brightfield. Phase contrast is used to reveal detail in indistinct objects, such as unstained cells and microorganisms that would otherwise appear invisible. By using a combination of specialized objective lenses and a modified light condenser, these invisible objects can be visualized by manipulating variations in phase. This contrast method provides far more detail than darkfield. The turret condenser not only provides the annuli needed for phase contrast, but also a brightfield setting with an iris diaphragm. This versatility makes life a lot easier by allowing you to switch between lighting methods by simply rotating a dial. The turret has two centering screws for proper alignment of phase-contrast settings. A telescopic centering eyepiece is also included for precise alignment, guaranteeing optimal results. Four plan-achromatic objective lenses are included, each equipped with a phase ring. These provide sharp, high-contrast images at magnifications from 10X to 100X. Condenser Compatibility Condenser Mount Bottom mount Mounting Diameter 37mm Model Compatibility B120, T120, M620 Condenser Specifications Condenser Type Turret design with phase contrast and brightfield Numerical Aperture 1.25 Immersion Medium oil Centerable Annuli Yes Phase Contrast 10X, 20X, 40X, 100X Objective Lenses Compatibility Optical System Finite Mechanical Tube Length 160mm Mounting Thread RMS 20.32mm Parfocal Distance 45mm Objective Lenses Magnification Corrections NA Cover-glass Thickness Immersion Medium 10X AchromaticPhase contrast 0.25 0.17mm — 20X AchromaticPhase contrast 0.40 0.17mm — 40X AchromaticPhase contrast 0.65 0.17mm — 100X AchromaticPhase contrast 1.25 0.17mm oil Contents: One turret condenser Four objective lenses (10X, 20X, 40X, 100X) One centering telescope