Funky-Looking Guardian Caps Rejected by NFL for Regulation Play, OK'd for Practice - Core77
Guardian Caps: What are they and why are NFL players wearing them? - Sactown Sports
Concussions among players who wore Guardian Caps over summer dropped more than 50%, NFL says - ESPN
Funky-Looking Guardian Caps Rejected by NFL for Regulation Play, OK'd for Practice - Core77
NFL reports reduction in concussions among players who wore Guardian Caps in preseason - The Athletic
Quarterback-specific helmet to be available during 2023 NFL season
NFL fans react to new guardian cap rules
Jarryd Hayne retires from NFL to pursue Olympic rugby sevens dream with Fiji, Jarryd Hayne
Robert Saleh dislikes the new Guardian Caps: And he has a point
NFL fans react to new guardian cap rules