NFL players don Guardian Caps, designed to protect from concussion
NFL hopes to reduce head injuries with helmet experiment
Puffy, spongy Guardian Caps could help curb NFL head injuries - The Washington Post
As NFL mandates Guardian caps in practice, area high school football teams have been using them for years, Sports
Football Guardian Cap draws mixed reviews from players, experts for safety effectiveness - The Daily Tar Heel
Steelers debut new, safer helmets for off-season training
NFL's use of Guardian padded helmet caps in camp draws support and skepticism - The Athletic
NFL players experiment with 'Guardian Caps' to protect heads – The Oakland Press
NFL mandates use of Guardian Caps for training camp in 2022 - Cincy Jungle
NFL hopes to reduce head injuries with helmet experiment
NFL CMO Dr. Allen Sills explains importance of mandated guardian caps during training camp
NFL hopes to reduce head injuries with helmet experiment
EXPLAINER: NFL using helmet caps for player safety, research
More padding the issue of concussions and better helmets