NFL players experiment with 'Guardian Caps' to protect heads
Guardian Caps The Rundown
Guardian cap' to prevent head injuries mandated for practices, CFL says
High school football looks to Guardian Cap for head safety
Staples football pioneers use of 'Guardian Caps'
What Pros Wear: Guardian Caps What are Those Helmet Covers Being Worn in Practice? - What Pros Wear
NFL announces more steps to reduce head injuries
Guardian Cap Use a Concern for Watt, Saleh Early in Training Camp - Sports Illustrated
Ravens Embrace the Funny-Looking Guardian Helmets - Sports Illustrated Baltimore Ravens News, Analysis and More
Concussions among players who wore Guardian Caps over summer dropped more than 50%, NFL says - ESPN
Guardian Caps leave some NFL players and coaches with concerns: 'You feel like a bobblehead'
Guardian Caps added to help reduce football concussions - The Witmarsum
Guardian Caps added to help reduce football concussions - The Witmarsum