A simple ring that can be used to make Heinz and some other brands of tin can able to stack on top of each other and lock together.

Other designs i found on here were just simple rings, or designs that themselves don't stack together, so if you use them you would end up with a bunch of rings in the cupboard that don't stack together neatly. This design makes it so the rings themselves stack together so you can keep a nice neat stack of them in the cupboard on top of a can, keeping them nice and neat.

Print doesn't need supports, i'd recommend setting top layers to concentric as even with a 0.8mm nozzle, depending on your wall count settings, there may be a narrow circular section on the inner lip that ends up mess to print with line pattern.