How does M21® Work?

It’s a mask that achieves  more.

The Problem

The traditional mask design, which is over 100 years old, was never intended for long-term daily wear by mass society.

For an entire century, its design has forced wearers to continuously breathe in their own recirculated, exhaled air, which can interfere with airflow and restrict oxygen intake. This leads to difficulty breathing and other issues such as:

Hypoxia & Hypercapnia

Inadequate oxygen supply at the tissue level and excess CO2 in the bloodstream. This can lead to shortness of breath, headache, and fatigue.


Immunosuppression and a threat to the body’s homeostasis. This can result to a weakened immune system and more susceptibility to infection and illness.


When breath passes back and forth through a traditional facemask, it increases the temperature and humidity between mouth and mask, causing toxic particles to release from the mask material.


Breathing through bacteria and germs present on the inner and outer layers of facemasks repeatedly cycles toxic components into the body.

Preliminary testing was done to evaluate the increase in CO2 in a traditional mask versus M21®. An increased CO2 level is associated with many health risks. M21® maintains consistent CO2 levels and enables better air exchange.

Measurements are in ppm (parts per million). This measurement is the mass of a chemical or contaminate per unit volume of water.

Decrease in CO2 Levels with M21® Mask Insert: N95 Mask

Decrease in CO2 Levels with M21® Mask Insert: Surgical Mask

250-350 ppm

Normal outdoor air level.

350-1,000 ppm

Typical level found in occupied spaces with good air exchange.

1,000-2,000 ppm

Level associated with complaints of drowsiness and poor air.

2,000-5,000 ppm

Causes headaches, fatigue, poor concentration, loss of attention. Increased heart rate and slight nausea may also be present.

>5,000 ppm

Unusual air conditions where high levels of other gases also could be present. Toxicity or oxygen deprivation could occur. This is the permissible exposure limit for daily workplace exposures.

>40,000 ppm

This level is immediately harmful due to oxygen deprivation.

The solution

The M21® Mask and M21+ Mask Inserts have a two-chamber design supporting the body’s natural breathing process, which is to breathe in through the nose and out through the mouth.

Breathing properly, especially while wearing a mask, is beneficial for the following reasons:


As we breathe through our nose, tiny hairs that line our nostrils can filter out particles that could injure our lungs.

Temperature Control

Another reason to breathe through the nose is that doing so can help warm and humidify the air to prepare it for our lungs.

Healthy Levels of O2 & CO2

Breathing properly helps maintain the correct balance of oxygen and carbon dioxide in the blood.

proper release of CO2

The main purpose of exhalation is to release carbon dioxide, which is a waste product. Exhaling through the mouth is the most efficient way to release CO2.

See How Easy M21+ Mask Inserts are to Install!

Face Masks Supplier Based in Philadelphia, PA

Below are the face mask inserts currently available. Select the option most appropriate based on the face masks that you and your family wear. Whether you wear a face mask for protection against allergins, pollutants, foreign particles, or disease, you’re one step closer to breathing better!

M21+™ Universal


M21+™ Surgical


Two Pack


Family Pack