Box fan filter bracket

This is an L bracket that can be mounted to the back of your 20inx20in box fan to hold a standard 20x20x1in filter. Just need one on each bottom corner and slide the filter in. I designed them so you can choose however you want to mount them to the fan be it glue,double-sided tape, rivets, screws they should be sturdy enough. If you plan on mounting hanging from the ceiling or plan on moving the fan a lot you can also add print the straight bracket to use as upper supports.