Couldn't find a forehead protection that suits my preferences for the DYE I4 mask, so just made one with better air circulation and fit to the head.

It straps to the mask by zip ties, and works very well.

Printed with Gyroid 3D infill, no supports / Made in Fusion 360

Works with DYE i5 masks also :)

Mask scan made by @ChrisE_93269 - Model available on Printables 

https://www.printables.com/model/1363573-dye-i4-mask-3d-scan