NFL players wear Guardian Caps to reduce head trauma during training camp
What is the NFL guardian cap and how does it work? – NBC Sports Bay Area & California
NFL Executive VP: League Saw 52 Percent Decrease In Concussions At Positions Wearing Guardian Caps - Steelers Depot
The potential solution to serious head injuries in football is counter-intuitive - Hogs Haven
NFL Mandates Guardian Caps During Training Camp - Team Insight
The Coat of Arms Added Protection or False Security: Football Tests New Guardian Caps to Prevent Concussions
What is a Guardian Cap? Meet the NFL's newest safety measure
First QB helmet designed to help reduce concussions approved by NFL, NFLPA
NFL players experiment with 'Guardian Caps' to protect heads - The San Diego Union-Tribune