Guardian Caps: Why some NFL players are wearing them in training
Explanation: NFL using helmet caps for player safety, research
Guardian Caps Guardian Sports
Football's Silent Killer Forces Players and Teams to Make Tough
New Football Helmet Could Save the Sport
NFL executive hints that Guardian Caps could eventually be worn in
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Virginia Tech lab releases first safety ratings for youth football helmets
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Guardian Caps Guardian Sports
NFL training camps: Guardian Cap players are wearing over helmets, why
Guardian Cap Results: “Exceeded Our Expectations”
NFL Presents: League-wide Guardian Cap Use to Reduce Head Impacts
How the NFL plans to play a season during the pandemic