I use these mainly to close herb bags, but I've found they're handy for all sorts packs, like breakfast cereals, tea leaf bags, etc.
The included 3MF has 10 of them. Just "right-click - Set number of instances" in PrusaSlicer to change how many you wish to print.
Also, don't forget you can scale them up for bigger bags (cereals).
The initial design was inspired by Paul Belcher's clip, but then I've re-drawn it from scratch and ended up changing basically everything about it and adding an extra spring feature.
You might be better off printing them from a stiff material (PLA, ASA). With PETG they might be a little bit too flexible, though the difference isn't big.
The author marked this model as their own original creation.