Quarterback-specific helmet to be available during 2023 NFL season
Guardian Caps Guardian Sports
Football Guardian Caps NXT (NFL Model)
Puffy, spongy Guardian Caps could help curb NFL head injuries - The Washington Post
Guardian Caps a fit for Park Wolfpack - Cottage Grove Journal
NFL executive hints that Guardian Caps could eventually be worn in games, along with position-specific helmets
What Pros Wear: Guardian Caps What are Those Helmet Covers Being Worn in Practice? - What Pros Wear
EXPLAINER: NFL using helmet caps for player safety, research
CFL players adjust to their bigger heads, helmet covers worn in practice