i found this nice fire hydrant ( https://www.thingiverse.com/thing:1360415 by Lucacri1) and wanted it to be functional, too.
so i did a little tinkercad magic et viola: the cover is removable and you can hide valuable things inside! :-)

tolerance between cover and hydrant is about ~0,5mm.
so it should fit on every printer out there!

HAPPY PRINTING and please share your makes