You can get Cambridge N99 masks on Amazon for about 20 to 30 dollars. I purchased one and carry it in my waistpack. When I inhale, I can feel the mask press against my face. When I exhale, the air doesn't just leave through the valve. Biggest problem I've noticed is I have to speak louder than normal, it muffles my breath.

I moved back to my work office from my home office yesterday. We now have 30-40% of the 700+ staff back in a phased approach to reopen. Waiting for me on my desk was a Welcome Back safety kit and a few extras.
1. Box of Kleenex
2. Monitor screen wipes
3. Disinfecting wipes
4. Hand sanitizer (Locally made)
5. Surface cleaner
6. 3 N95 masks (not the respirator style and Canadian made not Chinese!)
7. 3 re-usable cloth masks
8. Knickknacks for the desk
9. Welcome back snack & coffee from our VP.

I appreciated it all but considering I have a full beard, the masks are going to provide limited protection. It's more of a social consideration than medical necessity since my city hasn't had a Covid-19 case in over a month.

The building has various social distancing restrictions, like "walk this way" floor signage, restrictions on # of people in elevators and meeting rooms, and sanitizing stations everywhere. We filled out Hazard & Risk forms and had to watch videos on updated protocols, etc. No shaking hands, maintain 2 metre distance, cough into your sleeve, sanitize everything. Welcome back to our "new normal"!

The steadily widening recommendations for everyone to wear a mask is less to protect me from you, but to protect you from me.

The current estimate is that perhaps up to 40% of all new infections were transmitted from an infected person who was not having any symptoms, just simply breathing out the virus, in either respiratory droplets (currently thought to be most common means of transmitting or acquiring the infection), or the far smaller aerosolized viral particles, which can stay in the air for some dozens of feet (thought to be a less common means of transmission, although this is being challenged this week).

The PM 2.5 masks I've seen have expiratory valves, as do many of the N95, N99, N100 masks. If the wearer of a mask with an expiratory valve is asymptomatic or presymptomatic, yet infected, then every breath out through the valve is shedding virus. Wearing this type of mask, with an expiratory valve, puts others at risk.

I couldn't find "Cambridge N99" masks on Amazon.com.

Do note: If the mask has ear loops it is almost certainly not an N95 or better mask. It likely won't protect the wearer, but is fine for protecting others - so long as it doesn't have expiratory valves.

And huge thanks to Famdoc for pointing out the danger of expiratory (exhalation) valves. They should be taken off the market until the pandemic is history.

The "Cambridge" masks have a store front on Amazon but are backordered into August and not listing anything. I doubt their claim as well.

Amazon has gone way downhill in quality of their sellers/providers over the years. Especialy the last year or two. It isn't much better than eBay in the Trust category. You have to read a lot of reviews and get past the paid for ones.

All of the mask tips shared in this thread I already knew, but is it a good review for anyone who hasn't done their homework.

Still looking for a good source.

Stay healthy.

My Prime membership is expiring at the end of this month and I am considering canceling it.