Guardian Cap Use a Concern for Watt, Saleh Early in Training Camp - Sports Illustrated
NFL's use of Guardian padded helmet caps in camp draws support and skepticism - The Athletic
Puffy Guardian Caps Could Reduce NFL Player Concussions
Guardian Caps: The new helmets worn by several NFL teams
The Coat of Arms Added Protection or False Security: Football Tests New Guardian Caps to Prevent Concussions
NFL hopes to reduce head injuries with helmet experiment
Steelers debut new, safer helmets for off-season training
Why are NFL players wearing padding on helmets at training camp?
NFL says positions wearing Guardian Caps saw 52% decrease in concussions - NBC Sports
More padding the issue of concussions and better helmets
NFL hopes to reduce head injuries with helmet experiment
Eagles players on Guardian Caps: 'We look a little goofy,' but all for safety
Why are NFL players wearing padding on helmets at training camp?