What's with padded helmet caps teams are wearing
Chicago Bears: Why players are wearing padded helmets
Steelers debut new, safer helmets for off-season training
Puffy Guardian Caps Could Reduce NFL Player Concussions
Guardian Caps, a soft-shell helmet cover, among CFL's new player-safety initiatives
NFL Mandated Guardian Caps: Controversial Change - Sports Illustrated Seattle Seahawks News, Analysis and More
Could Guardian Caps be used in games? - NBC Sports
Guardian Cap Debuts at Training Camps League-wide
NFL players wear Guardian Caps to reduce head trauma during training camp
UGA football linemen wearing padded helmet covers designed to reduce impact
Puffy, spongy Guardian Caps could help curb NFL head injuries - The Washington Post
NFL training camps: Guardian Cap players are wearing over helmets, why