Guardian cap' to prevent head injuries mandated for practices, CFL says
NFL executive hints that Guardian Caps could eventually be worn in games, along with position-specific helmets
What Pros Wear: Guardian Caps What are Those Helmet Covers Being Worn in Practice? - What Pros Wear
Guardian cap' to prevent head injuries mandated for practices, CFL says
Guardian Cap Debuts at Training Camps League-wide
NFL report: concussions dropped 50 PERCENT when players wore new 'Guardian Caps' over the summer
NFL hopes to reduce head injuries with helmet experiment
Guardian Caps leave some NFL players and coaches with concerns: 'You feel like a bobblehead'
Guardian Caps NFL: What player positions are required to wear them?