Lightweight single use Collar safe for Cats, dogs and other pets

Print hollow (with 0% infill) with 1-2 walls and enough bottom/top layers to approximately match those wall's thickness. 
Pause the print after the handle finishes to insert your folded piece of paper.
Recommended to print with a 0.4 nozzle and a layer height of 0.2 or lower, ideally using a clear filament as to make the content obvious
Externally requires and is compatible with most keyrings.