In case you need a new or extra tray for your Invisalign retainers - here you go.

This is a hinged case that fits Invisalign style retainers. It is print in place without supports. 

It uses 2 6mmx3mm magnets that are press fit in the holes - I glued them down with some CA/super-glue.

I used 2 “painted” mouse-ear brims for the double hinge part, to ensure it sticks well to the build plate.