NFL training camps: Guardian Cap players are wearing over helmets, why
NFL says positions wearing Guardian Caps saw 52% decrease in concussions - NBC Sports
NFL on FOX - Guardian caps have significantly helped with the players health and safety during training camp this season. 🙏
The story behind those soft-shell puffy Guardian Caps players have been wearing
Puffy, spongy Guardian Caps could help curb NFL head injuries - The Washington Post
NFL players experimenting with 'Guardian Caps' to prevent head injuries
NFL executive hints that Guardian Caps could eventually be worn in games, along with position-specific helmets
Coverage of the NFL in Guardian Caps
Guardian Caps Guardian Sports
Guardian Cap debuts during minicamps in effort to reduce avoidable head contact
NFL players wear Guardian Caps to reduce head trauma during training camp