NFL CMO Dr. Allen Sills explains importance of mandated guardian caps during training camp
Puffy, spongy Guardian Caps could help curb NFL head injuries - The Washington Post
NFL's use of Guardian padded helmet caps in camp draws support and skepticism - The Athletic
What are Guardian Caps? NFL's latest padded helmets for added safety
Puffy, spongy Guardian Caps could help curb NFL head injuries - The Washington Post
More padding the issue of concussions and better helmets
NFL players' union calls for changes in concussion rules by Sunday
NFL concussion protocol: Details, history, policy - Sports Illustrated
NFL's use of Guardian padded helmet caps in camp draws support and skepticism - The Athletic