Guardian Caps debut at NFL training camps around the league
NFL CMO Dr. Allen Sills explains importance of mandated guardian caps during training camp
NFL makes Guardian Caps mandatory for many positions through second preseason game - NBC Sports
NYSportsJournalism.com - NFL Guardian (Caps) Of The Preseason Galaxy - Safety Impact: NFL Expands Presence As Guardian (Caps) Of The Preseason Galaxy
NFL Mandated Guardian Caps: Controversial Change - Sports Illustrated Seattle Seahawks News, Analysis and More
What is the NFL guardian cap and how does it work? – NBC Sports Bay Area & California
NFL's top doctor does not expect Guardian Caps to be worn in games
Guardian helmets worn in Training Camp
Why are NFL players wearing padding on helmets at training camp?
The story behind those soft-shell puffy Guardian Caps players have been wearing
Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN