Just a basic superhero style mask. As it is, it fits by pressure and friction, meaning it probably won't stay on under any sort of strain. Options include gluing elastic to the inside of the mask, gluing on with SFX makeup adhesive (like Spirit Gum), or drilling holes to tie a string or thong to.

Also included is a 2mm "slice" of the brow area, to make sure it fits. If the slice is too small or too large to fit over the center of your eyebrows, you can scale it until it does and not waste filament on a complete print. Just remember to transfer any scaling done to the mask, itself!