NFL players don Guardian Caps, designed to protect from concussion
Guardian Cap used by football teams to protect against head injury – The Denver Post
Queen's Football utilizing Guardian Caps - Queen's University Athletics
NFL's use of Guardian padded helmet caps in camp draws support and skepticism - The Athletic
Smith] NFL says positions wearing Guardian Caps saw 52% decrease in concussions : r/nfl
John's Journal: Park Football Team Is All In On Concussion Safety, News
Utah Utes football adds new concussion-reducing helmets for fall camp
Guardian Caps Guardian Sports
Guardian Cap debuts during minicamps in effort to reduce avoidable head contact
NFL's use of Guardian padded helmet caps in camp draws support and skepticism - The Athletic
Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN
Helmets don't eliminate concussions. It's time for the NFL to ditch them, NFL
EXPLAINER: NFL using helmet caps for player safety, research