Guardian XT Football Helmet Cap, Men's, White/Silver
What is a Guardian Cap? Meet the NFL's newest safety measure
Why Alabama football players are wearing padded helmets in practice
NFL players experimenting with 'Guardian Caps' to prevent head injuries
Why are NFL players wearing padding on helmets at training camp?
What are Guardian Caps? NFL's latest padded helmets for added safety
Guardian Caps leave some NFL players and coaches with concerns: 'You feel like a bobblehead'
NFL Health and Safety Fact Sheet
Guardian Cap: What are and why the NFL asks this safety measure in helmets
Seeking to reduce head contact, NFL mandates use of Guardian Cap helmet for early portion of training camp - ESPN
If a player wanted to wear a Guardian Cap during a game, the league would prohibit it - NBC Sports