Frequent Questions

If you don’t see your question about our face mask inserts below, please contact us!

What’s the difference between the two different M21+™ products?

There are currently 2 types of M21+ mask inserts available. The M21+™ Medical style is intended for surgical and N95 masks only, and attaches to the sides of the mask via a clip mechanism.  The M21+™ Slide was designed to slide over cloth masks, although it can also be used on traditional surgical and N95 masks as well.  ​

Does it come in different sizes?

Both styles of M21+™ are designed to fit all face contours for ages 10 years and older

How do I install the M21+ Medical and Universal inserts to a mask

Your M21+™ Medical and M21+™ Universal inserts slide easily into any mask and slip along the sides. Watch our videos to see how they work!


Can I use an M21+ mask insert with my cloth facemask?

Yes, absolutely! We recommend the M21+™ Universal if you are using a cloth mask. However, since cloth masks come in many different thicknesses and foldovers, we are pleased to offer the following tips for adding M21+™ to your cloth mask:


    • Take your time when raising the outer rim of the M21+™ Universal to start feeding the material through the slot
    • Use your thumb.on top and bottom of the plastic to support the end corners of the slot when pulling the material through the slot on each side. Although the M21+™ Universal is made from a durable plastic material, this additional caution will help prevent it from potentially snapping.
    • Feed the mask material through the slot side-to-side until the cloth is fully engaged through the slot, flat side-to-side, and slowly pull the cloth through the slot slowly supporting the slot corners.
    • Take your time – cloth mask materials are thicker than other reusable and disposable masks and often have very thick edging.
What type of material is used in the insert?

The material for the M21+™ mask insert is made of Prime High Impact Polystyrene, Natural, FDA Compliant

How long is M21+™ expected to last?

The M21+™ mask insert will last for years as long as it’s cleaned and handled properly. 

How should it be cleaned?

It is best to clean the M21+™ mask insert by hand using mild soap. 

Do you have a return policy?

Due to the personal wearable nature of the M21+™ mask insert, it is not returnable. 

Will M21+™ cause discomfort?

As long as it’s worn properly, the M21+™ mask insert will not cause any discomfort.  It is designed to improve the comfort of wearing a traditional mask. 

How will I know if M21+™ is working?

You will immediately notice better air quality and significantly reduced humidity in the nose chamber where users are encouraged to inhale.  When exhaling through the mouth chamber, users will notice they can immediately inhale better quality and cooler air through the nose chamber.

Do I need to buy a specific brand of mask?

The M21+™ Medical mask insert is suitable for any surgical or N95 mask.  The M21+™ Slide mask insert is intended for cloth masks, but is suitable for surgical and N95 masks as well.  M21+™ mask inserts for dome-shaped and duckbill mask types will be available soon.