Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:5194726.

There are allready tons of mask tensioners out there, but none are really customizable, and i had to do one for a child.

This one is done with openscad, you will need also https://github.com/nohkumado/nohscadlib if you want to use then yourselves, or i have to find somewhere the time/energy to make a working package...

but basically you can change in the customizer the length of the strap its thickness width, the number of chevrons and you can imprint a name on it