NFL's use of Guardian padded helmet caps in camp draws support and skepticism - The Athletic
Coaches approve of the Guardian Cap // Guardian Sports
Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN
Why the Ticats are wearing those giant helmets at practice
Can new technology help cut down on concussions? (video)
NFL Testing Validates Benefit of Guardian Cap on Helmets - Physical Therapy Products
Guardian Caps', NFL's Most Recent Attempt At Preventing Head Injuries
Football Guardian Caps XT
Reduces impact up to 33% One size fits all Insulates in hot & cold weather Fits both football and lacrosse helmets Connects to the facemask with 4
Guardian Protective Helmet Cover
NFL executive hints that Guardian Caps could eventually be worn in games, along with position-specific helmets
FOOTBALL: NFL following Sequim's lead with protective caps
Guardian Caps NFL: What player positions are required to wear them?
NFL's use of Guardian padded helmet caps in camp draws support and skepticism - The Athletic
Guardian Cap Debuts at Training Camps League-wide
NFL exec suggests Guardian Caps worn to protect players during practices could one day debut in games