Guardian Caps Guardian Sports
Guardian Cap: What are and why the NFL asks this safety measure in helmets
NFL's Decision to Ban Riddell VSR-4 and Schutt Air Advantage Helmets Explained
EXPLAINER: NFL using helmet caps for player safety, research - The San Diego Union-Tribune
Guardian Caps: NFL Requires Use Of Helmet Cover At Training, 46% OFF
Rising concussion awareness leads one high school to invest in high-tech football helmets, Sports
What Pros Wear: Top 5 Helmets Rated by the NFL & NFLPA - What Pros Wear
Coverage of the NFL in Guardian Caps
Guardian Cap debuts during minicamps in effort to reduce avoidable head contact