This is a model that allows easy tray stacking for a StayFresh Freeze Dryer. It fits over the corners of a tray, and allows placing another tray on top. The OnShape model allows configurable spacing between trays.
https://cad.onshape.com/documents/63aab56664da26c54f06ab6a/w/38599e5bea4c51db936cc8cf/e/564bc69a9ad9c32793548958?renderMode=0&uiState=64f7f0d188830659c6820519
The author marked this model as their own original creation.