This is an accessory for 3DUPfitters carbon air filter for 3D printer enclosures. Sometimes the back of the enclosure is too close to the wall for the air filter, so this moves it to the side.
Tyler's 3D Hub did a great job for the 80mm air filter, but the smaller enclosures now use a 60mm air filter. This is the same general idea, but a completely different design.
The fan side requires 4 M4 30mm screws. The filter side takes 3/5" #6 wood screws (2) on one side, and 2 M4 30mm screws on the other side. Note that the 2 holes on the filter side optionally require drilling holes in the enclosure for support.
Should use ABS or PETG in order to withstand the heat from the enclosure.