The transmitted electron adapter allows the SEM to function as a scanning transmission electron microscope (STEM). Beam electrons that pass through the sample are collected to form the image, while the secondary electrons that make up a traditional SEM image are excluded. While the adapter does not provide the resolution of a dedicated TEM or STEM, it is adequate for a wide variety of samples. Below are STEM images of a diatom frustule.

The schematic (PDF) for the adapter is specific to JEOL "T" series columns, but can be easily modified for other microscopes.