• How do I know which size is right for me?

Duos come in two sizes, medium and small. If you feel the Duos should fit more snugly, please let us know what size product you have (visible on the sample box in a box reading S or M) so we can adjust or consider the need for an extra size. The pod should seal your nostril completely.

  • When should I wear the product?

Outside and on the subway in polluted areas or if you are experiencing dust or pollen in the air. Most modern buildings, vehicles and offices are equipped with air-filtering systems.

  • How long can I wear the product for?

Although there is no prescribed limit to how long you should wear the pods, we don’t anticipate use of more than a few hours at a time. We want to hear what your experience is with wearing the pods and will be in touch after the test period.

  • Will wearing Duos affect my breathing?

We believe comfort is a primary requirement for the success of Duo. We are still developing our filters to make it easier to breathe through them. Depending on which filter samples you were given, breathability will be different. Let us know how you feel about comfort to help us refine our product.

  •  What particles am I protected against?

Duos are targeting PM2.5 particles which includes most of airborne pollution, they are about 40 times smaller than a human hair! They also capture larger particles like dust and pollen.

  • Is Duo N-99, N-95 , KN-95 rated?

    No, although we test our filters with similar protocols to N-99, N-95 an KN-95 test standards, since Duo does not protect the mouth, it cannot support any of these standards. 





  • Does Duo protect against COVID-19?

The short answer:

Duo offers some level of protection against COVID-19 spread.

The long answer: 

As we have all known since the start of the COVID-19 pandemic, Coronavirus is primarily transmitted from one person to the next through a cough, sneeze or speech when interacting with a contagious person. 

In these cases, most viral particles travel in tiny water droplets that are 5-10 microns (1000th of a millimeter) in size, of which Resprana Duos filter about 100% of particles. However, Duos do not prevent the same said droplet from entering the mouth or eyes during the same contact event. 

Furthermore, recent development in COVID-19 transmission studies in July 2020 have raised the likelihood of the virus being “airborne”, meaning the virus could also travel on its own, outside of water droplets in the air. COVID-19 virus particles span from 0.06 microns to .14 microns on average, particle sizes of which Duos are expected to capture fewer than 50%. 

It is not yet quantified how much of COVID-19 particles travel airborne vs in water droplets, and as of July 12th, 2020 the WHO has not yet confirmed airborne transmission of COVID-19 to Resprana’s knowledge. 


  • What protection is recommended to prevent the spread of COVID-19? 

Our recommendation remains to always wear a mask when Coronavirus protection is required. Masks are not only meant to protect the wearer from others, but also to prevent the wearer from contaminating others if he or she is contagious. Masks also limit the wearer from interacting with his or her face and thus protects further from virus transmission. 

Duos are an effective additional safety element that are encouraged to be worn in addition to a mask, particularly with cloth masks or masks that do not have N95 filters. Many masks don’t perfectly seal the airways around the face and Duo will offer a secondary barrier to contaminated air going into the nose.  

In the event other airborne threats such as pollution are present, Duo will supplement additional filtering protection some masks may not be rated or designed for.