This is a cutout ring for the Hamilton Beach 25475 Breakfast Sandwich Maker.
Should cut the bread, cheese, and meat to fit in the rings with a little room to spare.

Breakfast sandwich ring 2 makes for a tighter fit. Better for bread so that cheese does not ooze past the bread so easily.

This model is in inches. Most 3D printers will require the stl to be scaled (25.4mm/in) to print the correct size.
2 perimeters, 30% fill.