This might be a dumb question, but why do they wear these extra pads on their helmets for camp but remove them for games? : r/KansasCityChiefs
NFL Releases Concussion Data After Use of 'Guardian Caps' During Offseason - Sports Illustrated
Do padded helmet covers actually protect football players? - Futurity
Puffy, spongy Guardian Caps could help curb NFL head injuries - The Washington Post
Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN
Guardian Cap debuts during minicamps in effort to reduce avoidable head contact
NFL's use of Guardian padded helmet caps in camp draws support and skepticism - The Athletic
Guardian Caps: Why some NFL players are wearing them in training camps
Guardian Caps Guardian Sports
Puffy, spongy Guardian Caps could help curb NFL head injuries - The Washington Post
Puffy Guardian Caps Could Reduce NFL Player Concussions
These puffy helmet caps are the next big thing in NFL player safety, National Sports