ULTRA FIT Frequently Asked Questions (FAQs)

Product availability

How to get ULTRA FIT™ masks

The ULTRA FIT™ mask is currently only available on this site. Individuals and institutions can place an order here

Product attributes

Features and innovations in the ULTRA FIT™ mask

The  ULTRA FIT™ mask has a number of innovative features that allow it to make a superior seal against a user’s face, provide a high level of filtration, and remain highly breathable. No other low-cost, disposable mask can do this. See the test results from an accredited lab HERE. See this video on how to mold the mask to your face.

This chart compares a number of mask features for different mask designs

ULTRA FIT™ masks have been tested by an accredited laboratory (SGS IBR Labs) and meet the requirements of the ASTM F3502-21 specification. See test results HERE.

No. N95 respirators are intended for healthcare workers and, if used correctly, must be fitted to the user’s face in a specialized process called “fit testing.” A professionally fitted N95 respirator will provide more protection than an ULTRA FIT™ mask but will be much less breathable and much less comfortable than an ULTRA FIT™ mask. N95 respirators are designed for front line healthcare workers looking after COVID patients. N95 masks are not suitable for general community use, because most people will not reliably wear an uncomfortable mask in low risk community settings. ULTRA FIT™ masks are designed for comfort, compliance, and better protection than any other mask for general community use.

ULTRA FIT™ masks have not been approved for, nor should they be used for medical applications.

Katharos Labs performed a study on volunteers, 94% of whom said that the mask was as or more comfortable than other masks

There are multiple patents pending on a number of features of the mask

Wearing the ULTRA FIT™ mask

Putting on, taking off and why it is better

Click here (or visit www.katharos.info) for video instructions on how to properly wear an an ULTRA FIT™ mask. The process is similar to donning most other masks with two differences.

1) The ear loop elastics should be hooked through the length adjusters before donning then tightened/loosened after donning.  

2) The moldable wires along the edges should be pressed against the face and folded over either under the chin or along the sides to tighten the fit.

Because contaminants filtered by the mask may remain on interior and exterior mask-body surfaces after use, you should avoid touching those areas and remove the mask by touching only the ear loops, then dispose directly into an appropriate refuse container

The ULTRA FIT™ mask can significantly reduce eyeglass fogging caused by leakage of exhaled air. Make sure the wire along the top edge is closely molded to your face along the entire edge including tightly pinching across your nose. Fogging may still occur during cold weather or heavy breathing.

You may see descriptions of other masks talk about the effectiveness of the filter used in the masks; however, that is only half the story. Unless a mask seals closely to the face, contaminants may still pass around the masks. In fact, our testing has shown that a conventional surgical mask can allow 40% of all air to pass through gaps and completely miss being filtered. Cloth masks are also known for being ineffective, even if they have a replaceable filter. The combination of an effective filter, adjustable elastic tensioning and a close face seal make the ULTRA FIT™ mask a safer alternative to most other masks. In addition, since the ULTRA FIT™ mask is also highly breathable (see ASTM F3502-21 test results HERE), it is more comfortable over extended use times, making people more likely to use a mask.

Science behind the product

The ULTRA FIT™ mask has been extensively tested

The ULTRA FIT™ mask has undergone rigorous testing and evaluation using a variety of methods. See here for a description of the testing processes and results.

The filters used in ULTRA FIT™ masks are designed to let clean air pass, but trap any particles, droplets and aerosols in the airflow. The source of “smoke” for the laser-scatter smoke testing was water vapor, with a high density of particles between 0.25 and 0.45 microns, which is much smaller than typical respiratory droplets (in one study, the median particle size generated during talking was found to be around 80 microns). The smoke is essentially a tracer for all air flow through the filter and around gaps between the mask and the face.

Katharos Labs

About Katharos Labs, the company

The inspiration for Katharos Labs came from co-founders Dr. Anthony Samir (physician-scientist, Massachusetts General Hospital) and Dr. Jeff Karp (biomedical engineer and Professor of Anesthesia, Brigham & Women’s Hospital). Drs. Samir and Karp co-lead the N95 mask working group at the Mass General Brigham research hospitals COVID Innovation Center in Boston, MA. This group comprised 325 physicians,scientists, researchers, and makers from some of the most respected institutions in the United States. Drs. Samir and Karp realized at the beginning of the pandemic that existing mask technologies were neither designed for nor sufficient to mitigate community spread of the COVID-19 virus. Their key innovation was to produce a mask that combines excellent filtration with customizable excellent face seal technology.

The founders of Katharos Labs have substantial track records of successful medical technology innovation, translation, and commercialization. Our expertise spans across clinical medicine, engineering, materials science, mask engineering, and aerosol science. Click here to view a description of Katharos Labs’ Founders.

“Katharos” is a Greek adjective meaning clean, pure and free from contaminants, which is fitting for a mask that is superior at reducing contaminants passing to and from a wearer.