The darkfield condenser allows you to render detail in specimens that would otherwise be transparent. Using principles of light-diffraction to suppress field-illumination, the condenser illuminates edges of cells, microorganisms, and other objects. This is particularly useful for live blood analysis. This is a darkfield condenser designed for dry use with lower magnifications. The 0.9 maximum numerical aperture will accommodate lower-magnification objective lenses with numerical apertures up to 0.9. However, it is recommended to use objective lenses with numeical apertures below 0.7 for true darkfield. For magnifications above 40X, it is recommended to use the oil condenser. This condenser is designed to work with compound microscopes with a 37mm front-mount condenser holder. Compatible models include: T670, T670Q-PL, T750, FM820T Condenser Compatibility Condenser Mount front mount Mounting Diameter 37mm Model Compatibility T670, T670Q-PL, T750, FM820T Condenser Specifications Numerical Aperture 0.7-0.9 Immersion Medium none