What are Guardian Caps? Shadow Hills football using new device to reduce head injuries
Tennessee football: UT Vols use Guardian helmet covers
Guardian Caps Guardian Sports
If a player wanted to wear a Guardian Cap during a game, the league would prohibit it - NBC Sports
NFL executive hints that Guardian Caps could eventually be worn in games, along with position-specific helmets
Guardian Caps added to help reduce football concussions - The Witmarsum
Guardian Caps (@guardian_caps) • Instagram photos and videos
NFL hopes to reduce head injuries with helmet experiment
Guardian cap' to prevent head injuries mandated for practices, CFL says
NFL exec suggests Guardian Caps worn to protect players during practices could one day debut in games
High school football looks to Guardian Cap for head safety – The Denver Post