This thing was designed for use in the forepeak of my power boat.
It can have many other uses regarding ventilation, ex. cover up of vent/fan holes.
My use for this item is to cover 2x vent holes in the forepeak on my boat wich was made to create air circulation and hopefully reduce the amount of condensation.

I printed this in PETG (any material wich fits your enviroment will do)

4x perimeters to make it a bit more stronger round the edges and holes
4x 4mm holes
dimensions 100mm x 100mm

Prusa

No

0,15mm