Here's why some Patriots players are wearing caps over their helmets during training camp
What is the NFL guardian cap and how does it work? – NBC Sports Bay Area & California
Large Bubble Helmets Are Guardian Caps, NFL's New Safety Measure
NFL Expands Use Of Guardian Caps In 2023 - Steelers Depot
Steelers debut new, safer helmets for off-season training
Seeking to reduce head contact, NFL mandates use of Guardian Cap helmet for early portion of training camp - ESPN
Guardian Caps debut at NFL training camps around the league
Guardian Caps Debut at Training Camps Across the NFL
NFL Makes Ruling On Players Wearing Guardian Cap During Game - The Spun: What's Trending In The Sports World Today
NFL training camps: Guardian Cap players are wearing over helmets, why