This is a lid for round plastic or glass tubs, like the ones yogurt comes in. Open it in The Customizer to modify it for whatever container you have that needs a lid.

I wouldn't use these for food, unless you print the lid in a food-safe material. TPU is a good choice for a more flexible lid that can be snapped onto a rigid container.

To show how customizable this is, I've also included an STL for a TPU beer bottle cap.