Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN
Guardian Cap debuts during minicamps in effort to reduce avoidable head contact
Kenny Pickett Changed Helmet After Second Concussion: 'I Definitely Want To Be Safe' - Steelers Depot
So what exactly is that black padding on the Syracuse football helmets seen during practice?
NFL executive hints that Guardian Caps could eventually be worn in games, along with position-specific helmets
Jason Kelce puts bubblewrap on his helmet, mocking the NFL's dumb new Guardian Cap rules in training camp
Guardian Cap debuts during minicamps in effort to reduce avoidable head contact
The story behind those soft-shell puffy Guardian Caps players have been wearing
Shell game: Player safety looming concern as new season approaches, Local Sports
Football helmet - Wikipedia
Guardian Caps: NFL Requires Use Of Helmet Cover At Training, 46% OFF
What are Guardian Caps? NFL's latest padded helmets for added safety