Guardian Cap Results: “Exceeded Our Expectations”
NFL training camps: Guardian Cap players are wearing over helmets, why
Chicago Bears: Why players are wearing padded helmets
NFL players wear Guardian Caps to reduce head trauma during training camp
Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN
Have you seen the strange helmets Cowboys players are wearing in camp? Here's the story
MTSU reduces concussion risk with padded helmet covers
Guardian Caps Guardian Sports
Large Bubble Helmets Are Guardian Caps, NFL's New Safety Measure
Vicis expands helmet line with new soft 'cap' for practices, 7-on-7 and flag football – GeekWire
Patriots, rest of NFL wearing cushioned helmet caps at training camp, per new mandate - CBS Boston