First QB helmet designed to help reduce concussions approved by NFL, NFLPA
Steelers debut new, safer helmets for off-season training
What in the world are those weird-looking helmets the Saints are wearing in camp?, Rod Walker
Cowboys Players Wearing Strange New Helmets at Training Camp – NBC 5 Dallas-Fort Worth
Guardian Caps debut at training camps throughout NFL
Giants react to NFL's new 'Guardian Caps' at training camps - Big Blue View
EXPLAINER: NFL using helmet caps for player safety, research
Coronavirus: NFL suggests face shields on helmets - Los Angeles Times
NFL executive hints that Guardian Caps could eventually be worn in games, along with position-specific helmets
NFL Players Seen Sporting Futuristic New Helmets During Training Camp (PICS)
Vikings Introduce Soft-Padded Helmets for Parts of OTA Practices
NFL CMO Dr. Allen Sills explains importance of mandated guardian caps during training camp