Guardian Cap: What are and why the NFL asks this safety measure in
NFL's use of Guardian padded helmet caps in camp draws support and
Funky-Looking Guardian Caps Rejected by NFL for Regulation Play
NFL: Concussions dropped by more than 50% among players who wore
Funky-Looking Guardian Caps Rejected by NFL for Regulation Play
NFL mandates extra head protection for training camp
Guardian Caps: NFL requires use of helmet cover at training camps
NFL executive: Guardian Caps could one day be used in games
Giants react to NFL's new 'Guardian Caps' at training camps - Big
NFL players wear Guardian Caps to reduce head trauma during
Guardian Caps Guardian Sports