I made these for my Bathroom door, the lanlord had drill some holes in it for bether ventilation, and it dident look so nice, so i designed and printed these to make it loke somewhat bether. i guess you could scales these to size for any round ventilation hole you might have. please enojy.

I hade to increase it 1% to make it fit the holes really tight, but you figure it out. ;)

its made to fit a 73 mm hole but its more like 72.50, when i increase it 1% it i measure 73,50