NFL hopes to reduce head injuries with helmet experiment
Ohio State Aiming To Reduce Head Injuries With Guardian Caps - Sports Illustrated Ohio State Buckeyes News, Analysis and More
Funky-Looking Guardian Caps Rejected by NFL for Regulation Play, OK'd for Practice - Core77
Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN
Funky-Looking Guardian Caps Rejected by NFL for Regulation Play, OK'd for Practice - Core77
Colleges add Guardian football protective helmet cap - Sports Illustrated
Puffy, spongy Guardian Caps could help curb NFL head injuries - The Washington Post
NFL's use of Guardian padded helmet caps in camp draws support and skepticism - The Athletic
Guardian Cap Debuts at Training Camps League-wide