Coverage of the NFL in Guardian Caps
Guardian Cap Debuts at NFL Training Camps League-wide
NFL training camps: Guardian Cap players are wearing over helmets, why
Large Bubble Helmets Are Guardian Caps, NFL's New Safety Measure
What in the world are those weird-looking helmets the Saints are wearing in camp?, Rod Walker
The 2022 Uni Watch NFL Season Preview - by Paul Lukas
Funky-Looking Guardian Caps Rejected by NFL for Regulation Play, OK'd for Practice - Core77
NFL introduces Guardian Caps across league to limit number of brain injuries in preseason