Seeking to reduce head contact, NFL mandates use of Guardian Cap helmet for early portion of training camp - ESPN
NFL hopes to reduce head injuries with helmet experiment
Guardian cap' to prevent head injuries mandated for practices, CFL says
What Pros Wear: Guardian Caps What are Those Helmet Covers Being Worn in Practice? - What Pros Wear
NFL executive hints that Guardian Caps could eventually be worn in games, along with position-specific helmets
Guardian Caps Guardian Sports
Utes using protective Guardian Caps in fall camp
Coverage of the NFL in Guardian Caps
Guardian Caps, a soft-shell helmet cover, among CFL's new player-safety initiatives
The safety story behind the unusual helmets NFL players are wearing this summer - OHS Canada MagazineOHS Canada Magazine
Robert Saleh dislikes the new Guardian Caps: And he has a point
What Pros Wear: Guardian Caps What are Those Helmet Covers Being Worn in Practice? - What Pros Wear
Guardian Cap debuts during minicamps in effort to reduce avoidable head contact