Jets' Robert Saleh is concerned about impact of Guardian Caps on player safety
NFL Presents: League-wide Guardian Cap Use to Reduce Head Impacts
EXPLAINER: NFL using helmet caps for player safety, research
New York Jets coach Robert Saleh says he's concerned over use of new protective helmet shells - ESPN
NFL Makes Ruling On Players Wearing Guardian Cap During Game - The Spun: What's Trending In The Sports World Today
Guardian Sports - Guardian Caps Testimonials
Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN
NFL CMO Dr. Allen Sills explains importance of mandated guardian caps during training camp
What are those funny-looking soft caps on NFL helmets during camp?
Raiders, other NFL teams wear Guardian Caps for head safety, Raiders News
What is a Guardian Cap? Meet the NFL's newest safety measure
Guardian Caps - Are the soft-shelled football helmet covers effective at limiting head injuries? - ESPN