Here's why some Patriots players are wearing caps over their helmets during training camp
NFL mandates use of Guardian Caps for training camp in 2022 - Cincy Jungle
Puffy Guardian Caps Could Reduce NFL Player Concussions
EXPLAINER: NFL using helmet caps for player safety, research
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Saints adjusting to use of Guardian Caps in training camp - Daily Leader
NFL says Guardian Caps reduced concussions by more than 50%
NFL CMO Dr. Allen Sills explains importance of mandated guardian caps during training camp
Cowboys seen wearing protective, NFL mandated Guardian Caps at OTAs
NFL players experiment with 'Guardian Caps' to protect heads
NFL: Concussions dropped by more than 50% among players who wore Guardian Caps during summer
NFL players wear Guardian Caps to reduce head trauma during training camp
NFL players experiment with 'Guardian Caps' to protect heads
Guardian Caps: Why some NFL players are wearing them in training camps
NFL players beginning to adopt protective Guardian Caps over helmets at practice - NBC Sports