How to build a Tetra PAPRa Mask (v1)

The Tetra Powered Air Purified Respirator requires a Mask component to deliver purified air to the face of the wearer. This mask will be connected to the Fan Box via a CPAP hose. In our testing of the mask, it has been comfortable to wear for several hours, and provides protection while the device is powered on. When the device is powered off, the mask is not effective, and so we are still iterating on the mask design to provide protection when the device is powered off. A single battery charge can provide up to 4 hours of protection, which is sufficient for many use cases for us to feel comfortable publishing this mask.

This photo shows all the parts laid out for building this component:

You will need these components. Prices fluctuate, and so are not included here. Alternative versions can be sourced, and we welcome edits for tested alternatives.

These tools are recommended. URLs are for tools purchased and used in the building of the prototypes:

Once the mask has been printed, the build consists mainly of getting the 3-ply Medical Face Mask material onto the mask so that the wearer’s exhalations can exit the mask without affecting those around them.

Place the 3-ply mask over the circular hole in the face mask, and then place the o-ring over the 3-ply mask. The blue side of the face mask should be facing out:

You may need to cut the mask before the o-ring will fit:

Once the o-ring is in place, cover the mask with the Cover Frame, which should snap in place:

Trim any excess 3-ply material around the edge of the seal:

Attach the CPAP hose to the Mask and Fan Box:

Push the bathing suit elastic through the attachment points on the mask as one long strand. Some prefer to tie at the top of the head, while others may prefer behind the neck. Note how the elastic emerges from behind the attachment points to wrap around the head and neck:

Congratulations! You now have a TETRA PAPRa face mask!

Changing the filter depends on how much you use the device. If you’re using the device where there are a lot of particulates in the air (such as a construction site or a woodshop), you may want to change every few days or so. If you’re using the device where there are less particulates, every two to three weeks should be fine. If the filter material gets dirty or wet, you should change it. The blue layer is intended to be water proof, but we don’t know how much actual water it can take.