Most masks we sell are one size fits all. They are adjustable. The key measurement from the top of the mask to the bottom is almost always more than enough for most people. The extra space around your head is taken up with the adjustable or rubber straps.

A general rule of thumb for our masks made by Respro is that they fit small. Our 3M Respirators run a little large with regard to the top and bottom measurement. With the 3M Respirators, it’s good to keep in mind that though they have some give and adjustability in them, they do not have as much leeway in them as the Respro models because of the fabric.

A quick way to get a better fit is to measure your face. At this point, you need to take a ruler, stand in front of the mirror, and do a quick measurement from the bottom of your chin to the middle of the nose (roughly just above the nostrils since you don’t want the mask to rest up by the eyeballs on the bridge of the nose).

Take this measurement and compare to some of our masks. Mask distance from top to bottom:

• Respro Aero Small – 4” --- fits people with small face and children. Also, keep in mind that unless you have a very small head, the chances are that you it will not fit around your head.
• Respro Aero Medium – 4.5” --- fits most women.
• Respro Aero Large – 4.75” --- fits most men.



• Respro Techno M – 4.75” --- fits most women and some men.
• Respro Techno L – 5.125” --- fits most men.



• 3M 6291 Mask --- 4.75”
• 3M 6391 Mask --- 5.0”

*Please note that these measurements are approximate and that all of the masks have some give in them.

Please use this guide to help you when you are choosing which mask is best for you. Also, keep in mind that every mask has different filters and applications. Depending on your allergy and asthma needs, the actual fit of the mask might be secondary to filter capabilities of the mask.