What are Guardian Caps? NFL's latest padded helmets for added safety
Guardian Caps Exceed NFL's Expectations - Guardian Sports
NFL hopes to reduce head injuries with helmet experiment - Seattle
CFL players adjust to protective helmet caps
What are those funny-looking soft caps on NFL helmets during camp
Guardian Cap Debuts at NFL Training Camps League-wide
If a player wanted to wear a Guardian Cap during a game, the
High schools try to cap concussions
Football helmets with outside padding get tryout at Bremerton High