A very versatile tool that should be in every wallet.
It has a standard card side with slightly higher thickness (2.5mm), but I have yet to find a wallet that it does not fit in.
It should be printed in food-safe(ish) materials, such as PLA and PETG!
The model is optimized for FDM printing and does not require any supports. From my tests, a layer height of 0.12mm gives the best results.
Beware that the card is single-use only, as the layer lines could hold onto food and will be a prime spot for bacterial growth after the first use.
Here is also a video: https://www.youtube.com/watch?v=n4fPUnxHct4