Geocaching PET Lock

This is a little structure which lets you put a padlock on a PET bottle piece (in Germany known as a "PETling").

See attached photos about how to use this thing.

All you need to buy extra is a padlock where the clip has a maximum diameter of 7mm.

I'll also upload the scad file which I wrote to create this thing, although it was written quick & dirty and could still be optimized.

Originally the PET lock was intended as a wedding gift where the PETling hold some money and the newlyweds