The Oakley “Mouth Shield” referenced in the article attaches to the face mask (rather than actually being worn on a player's mouth).
Here's the prototype: [
www.espn.com]
This is how Dr. Jeff Crandall, chairman of the NFL's Engineering Committee, describes the mouth shield: "Clear plastic with slits or holes in it that block any direct path of a droplet, but do promote air flow, communication, soundwaves," [
www.nfl.com]
FWIW "well over 700 players" wore a visor last year (out of around 1,700 players). The "mouth shield" is essentially an extension to the visor that many players already use.
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