What Pros Wear: Guardian Caps What are Those Helmet Covers Being Worn in Practice? - What Pros Wear
NFL CMO Dr. Sills on Guardian Caps Mandate >> Guardian Sports
Guardian Caps: NFL requires use of helmet cover at training camps to reduce head injuries
Puffy, spongy Guardian Caps could help curb NFL head injuries - The Washington Post
NFL executive hints that Guardian Caps could eventually be worn in games, along with position-specific helmets
Could Guardian Caps be used during NFL games for player safety?, Pro Football Talk
Guardian Cap Results: “Exceeded Our Expectations”
What are Guardian Caps? NFL's latest padded helmets for added safety
What Pros Wear: Guardian Caps What are Those Helmet Covers Being Worn in Practice? - What Pros Wear