I don't know if it will help, but we have a hierarchy of masks best to worst:
Assuming NO EXHALATION VALVES for any mask
NIOSH-certified N95 to P100 masks
Surgical mask, ASTM-compliant Level-1 (or better)
Cloth mask, two layers with face shield.
Cloth mask, two layers alone
Any old cloth
shield alone is a no-no.
The site you reference shows a mask with an exhalation valve at the top which tells you this is not a source that has any sense. The clear masks have no kind of approval or test rating available.
There is a mask called the "Communicator" that is at least ASTM-compliant. it has a small clear panel. it is not approved for hospital use by FDA, but at least it has some credentials. Google it. If you can't find it, get back in touch.
Monona
-----Original Message-----
From: Tammy M. Lutz-Rechtin <tlutzrec**At_Symbol_Here**UARK.EDU>
To: DCHAS-L**At_Symbol_Here**Princeton.EDU
Sent: Tue, Aug 4, 2020 5:10 pm
Subject: [DCHAS-L] Clear masks for teaching?
What does everyone think about the use clear window masks for teaching? We want to be safe and increase effective communication.
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