Guardian Caps: The new helmets worn by several NFL teams
EXPLAINER: NFL using helmet caps for player safety, research
Guardian Cap Use a Concern for Watt, Saleh Early in Training Camp - Sports Illustrated
Packers share thoughts on wearing Guardian Caps at camp
Guardian Caps Guardian Sports
Cowboys seen wearing protective, NFL mandated Guardian Caps at OTAs
What are Guardian Caps and how are they helping football teams?
Eagles players on Guardian Caps: 'We look a little goofy,' but all for safety
Guardian Caps: Why some NFL players are wearing them in training camps
NFL hopes to reduce head injuries with helmet experiment
NFL players experiment with Guardian Caps // Guardian Sports