Garber Dukes to wear Guardian Caps during football practices
NFL executive: Guardian Caps could one day be used in games
The story behind those soft-shell puffy Guardian Caps players have been wearing
NFL says positions wearing Guardian Caps saw 52% decrease in concussions - NBC Sports
NFL says Guardian Caps reduced concussions by over 50%
NFL hopes to reduce head injuries with helmet experiment
Padded helmet cover shows little protection for football players - Scope
Guardian Caps The Rundown
NFL's use of Guardian padded helmet caps in camp draws support and skepticism - The Athletic