These are some other parts, used for alignment and other purposes.
![Image: direct_beam_stop](https://muse.union.edu/hollochk/files/2021/08/direct_beam_stop.jpg)
Beam-blocking tool, used in some low-angle modes to keep the direct beam from entering the detector.
![Image: center_slit_alignment_tool](https://muse.union.edu/hollochk/files/2021/08/center_slit_alignment_tool.jpg)
Center slit alignment tool, generally used at the beginning of each day to align the optics.
![Image: brass_alignment_slit](https://muse.union.edu/hollochk/files/2021/08/brass_alignment_slit.jpg)
I suppose this is an alignment slit, though I don’t know exactly what sort of alignment.