Air Gear Wool Pre-Filter

I designed a 3D-printable wool pre-filter that mounts directly in front of the standard charcoal filter supplied with the AirGear Pro gas mask.

I’ve always preferred using wool in front of my filters because it’s excellent at trapping not only smoke but also fine airborne particles such as paint mist. This approach has a big advantage: instead of replacing the entire charcoal filter, I can simply remove and replace the wool in the pre-filter. This makes the charcoal filter last significantly longer, protecting it from dust, chemicals, and splashes before they ever reach it.

Wool is inexpensive—less than three euros for a large pack—and easy to replace.

Design details:

The pre-filter consists of two printed parts: a bottom piece and a top cage.

The bottom part fits snugly on top of the AirGear Pro charcoal filter. I 3D-scanned the charcoal filter to ensure a perfect fit.

The top part forms a cage to hold the wool in place. You can remove the top to replace the wool, either by pre-packing the cage or by stuffing small chunks of wool inside for convenience.

Everything is designed for easy printing—no supports and no additional tools required.

How it works:

Place the bottom part over the charcoal filter.

Add wool inside the top cage (either in small chunks or packed beforehand).

Attach the top to the bottom—your pre-filter is ready to go.

This simple addition greatly increases the lifespan of your charcoal filter while keeping your mask highly effective against particulates.

Print settings:

No supports needed

Material: PLA, PETG, or other suitable filament

Layer height: 0.2 mm recommended