EXPLAINER: NFL using helmet caps for player safety, research
What's with padded helmet caps teams are wearing
Guardian Caps Guardian Sports
NFL executive hints that Guardian Caps could eventually be worn in games, along with position-specific helmets
Guardian Caps: NFL requires use of helmet cover at training camps to reduce head injuries
NFL's use of Guardian padded helmet caps in camp draws support and skepticism - The Athletic
Safety first: Lopers to wear padded caps in practice to prevent concussions
Why guardian caps are now part of practice helmets for certain Titans
NFL says positions wearing Guardian Caps saw 52% decrease in concussions - NBC Sports
Guardian Caps debut at NFL training camps around the league
Bellmore-Merrick athletics debuts new guardian caps, Herald Community Newspapers
Arizona Cardinals defensive end J.J. Watt not fan of the new league-mandated Guardian Caps on helmets