I found this mysterious metal part on my kitchen floor. It is metal, 7cm in diameter, and not a complete circle. The shape is slightly polygonal rather than perfectly round. The grid in the image is 7mm (~1/4").
I think only toaster and robot vacuum (Ecovacs T10) have been operated in the area recently. Nothing obvious is missing from them, but it is about the same size as the robot vacuum's wheel.
Could it be from the robot vacuum, or possibly from some other kitchen appliance like a blender or food processor? I haven't been able to trace it back to anything yet.