Add on nose adjusters add extra adjustability to your mask. Applying a nose adjuster to the nose bridge of your masks closes off gapping around your cheeks and prevents airflow, which can fog glasses and allow particles in and out of your mask. These adjusters can be added to any masks, including ones purchased elsewhere.
Many mask manufacturers build their adjusters directly into their masks. Through use and washing, these adjusters break down over time and become no longer usable. By using adhesive strip adjusters on the OUTSIDE of your standard cloth or disposable masks, you are able to replace them when they are no longer usable, while continuing to use your masks.