Guardian Caps: What Are They & How Do They Work?
Guardian Cap Use a Concern for Watt, Saleh Early in Training Camp
Arizona Cardinals defensive end J.J. Watt not fan of the new
EXPLAINER: NFL using helmet caps for player safety, research
Padded helmet cover shows little protection for football players
Bombers welcome introduction of new safety gear – Winnipeg Free Press
Guardian Caps Guardian Sports
How Irish are taking more safety measures when it comes to concussions
NFL, NFLPA working hard to improve player safety
Florio PFT] The Guardian Cap apparently works. But if a player
More Guardian Caps, And '0' On The Field