These make it easier to grow adherent mammalian cells on grids without bending the grids. The large dishes fit in 6 well plates. The small dishes were designed to fit in 35 mm Mattek glass-bottomed dishes with a 20 mm glass insert:

https://www.mattek.com/store/p35g-1-5-20-c-case/

The small dishes should snap into place. If they are not a tight enough fit, a dab of autoclaved silicone grease on the bottom can hold them down, similar to a cloning ring. The 19.65 mm dish is a slightly tighter fit. Before using, I soak the dishes in ethanol and let them dry completely before adding cell culture media to them.

NOTE: These files were created when I was still employed at the National Cancer Institute within the National Institutes of Health (NCI Ref No. E-243-2016 (TEM)). From the NIH licensing office: "This transfer is being made as a service to the research community for use within your laboratory and may not be used in human subjects. NIH disclaims any liability resulting from your use of the software. Please acknowledge the NCI source of the software in related presentations or publications."