Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN
Packers share thoughts on wearing Guardian Caps at camp
Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN
NFL Network: Guardian Caps in use at training camps
NFL Makes Ruling On Players Wearing Guardian Cap During Game - The Spun: What's Trending In The Sports World Today
Guardian cap' to prevent head injuries mandated for practices, CFL says
What are Glacier Peak players wearing on their helmets?
NFL players don Guardian Caps, designed to protect from concussion
Guardian Caps leave some NFL players and coaches with concerns: 'You feel like a bobblehead'