This model is based on Mars3D's (Print-in-Place) FlipFlop Buttons).
Compared to the original, it has no text, a hole for a keychain, and is 30% bigger.
The following is from Mars3D:
"Print-in-Place FlipFlop Fidget Buttons
A compact, stress-relieving gadget designed for endless tactile satisfaction. This fidget toy is perfect for anyone who enjoys flipping, pressing, and fidgeting to stay focused or calm their nerves. The Print-in-Place FlipFlop Fidget Buttons are designed to be printed as a single piece with no assembly required, making it an excellent project for 3D printing enthusiasts of all levels.
I have tried to ensure this design has minimal friction for maximum comfort. If something is not right, please feel free to write to me so I can try to improve it.
The author remixed this model.

This model has no text, is 30% bigger (so it fits your hand better), and has a hole for a keychain.