It's coin piggy bank with special Maze Thread. It put some effort to open it. Good for kids, and adults too.
Gap between the tread/slot and the pin , is 0.3mm that I believe considerably safe for 3D printing.
It consist of The body and The Lid. the Volume is about 1Liter,
if you want the bigger one, such as 2 L , Just let me know at comment below.
This thing is some of my merchandises for my Youtube Channel.