Before I get fully into the verdict, if you hadn't already checked it out from the newsletter link, here's some information from the Cambridge Mask Co. website ...
"Cambridge Masks™ are respirators that use military grade filtration technology to filter out nearly 100% of particulate pollution, gases, as well as bacteria and viruses in a fashion friendly mask suitable for the whole family. Cambridge Mask’s™ inner filtration layer is made from a 100% pure activated carbon cloth, which was originally invented by the UK Ministry of Defence. It was extensively developed and has been made into products for use in chemical, biological and nuclear warfare protection."
"Our pollution masks help protect against gas based pollution, such as smells, benzene and formaldehyde, particle pollution such as PM2.5, pollen or smoke and pathogens such as viruses and bacteria. Ideal for cyclists, people in at risk groups for respiratory disease or anyone living in urban environments with high air pollution levels ..."
I chose a small size. I wanted a firm fit to be affective. I was concerned it might be too restrictive but it quite comfortable. I thought the firmness of the ear straps may cause my ears to resemble the airplane wings, but this wasn't the case.
The fit was snug, but not as airtight as I thought it would be. It was still effective, though.
There is a certain freshness the mask may lack if don't plan on cleaning your teeth a couple of times over a 13 hour flight. I dabbed 'Medieval oil' on the inside, a combination of herbal essential oils designed to provide some immunity. I find it a pleasant smell and thought it couldn't hurt in order to prevent people from 'sharing.' I was expecting the mask to prevent me from noticing smells and odours, but this wasn't totally the case.
My breathing wasn't restricted at all, despite the mask rising and falling slightly with respiration. This eased "the easy fit but effective barrier" comparison in my mind. In fact, the mask conformed so well that, in my experimentation, I was able to wear if upside down and still find it worked!
I wore the mask from the moment I sat down in Brisbane to the moment I disembarked in LA, except for eating (and teeth cleaning!).
In the end, the major questions I had of the mask were: would it keep me healthy and would I feel less jet-lagged? This is important because I'm almost straight into long hours of learning and practice as soon as I'm there. The overall verdict is 'yes'. I felt better. From a physiological point of view, rebreathing your own carbon dioxide should provide a parasympathetic (calming) response. I wasn't any less tired, after all, a lack of sleep is a lack of sleep; and eating and operating in majorly different time zones is still a problem. However, I would say that I felt 'cleaner'. I had less brain fog and my whole system generally felt lighter. I think this translated into a shorter adjustment period, both when I got there and upon my return.
Overall, I'd say thing if international travel or frequent domestic trips were your thing, rather than robbing banks, then check it out.