NFL introduces Guardian Caps across league to limit number of brain injuries in preseason
Guardian Caps debut at training camps throughout NFL
What are Guardian Caps? Shadow Hills football using new device to reduce head injuries
Guardian Cap used by football teams to protect against head injury – The Denver Post
NFL hopes to reduce head injuries with helmet experiment
Eagles players on Guardian Caps: 'We look a little goofy,' but all for safety
NFL players experiment with 'Guardian Caps' to protect heads - The San Diego Union-Tribune
Guardian Caps: NFL requires use of helmet cover at training camps to reduce head injuries
NFL says Guardian Caps reduced concussions by over 50%
Thoughts on Guardian Caps for Concussion Prevention - Smith Physical Therapy & Running Academy
Puffy, spongy Guardian Caps could help curb NFL head injuries - The Washington Post