A couple modifications: Vent holes to release heat, tabs on the front to allow 3-hole punched sheet protector to be used, and the internal head band is angled at 10 degrees to sit better on the head. The slit in the forward band is still there in case you want to use the original option. I would still recommend the use of foam as Jeremy stated. Also, use what you have to hold it on.

Shout out to Jeremy to get this out there.

Good luck to everyone, stay safe and happy printing.

Jeremy face shield covid-19 by jeremy089786 April 06, 2020 https://www.thingiverse.com/thing:4266645