N.F.L.'s Release of Data on Helmet Tests Raises Concerns - The New York Times
Vicis high-tech helmets take top 3 spots in NFL's annual performance ranking of equipment – GeekWire
Varsity Football Helmet Ratings
Xenith helmets take the field in the NFL
How to Fit a Football Helmet, Xenith
Protective helmets make sports safer
Detroit's Xenith Introduces the Xenith Shadow XR Football Helmet - DBusiness Magazine
Football helmet joins fight vs. head injuries - The Boston Globe
Dan Gilbert-backed football helmet maker is butting heads with big industry players
Xenith X2E+ Youth Football Helmet - Adaptive Fit, White / M
Xenith Helmet Voluntary Recall