NFL to prohibit use of certain helmets for the first time, NFL
The NFL calls Vicis Zero1 helmets the safest yet
Vicis Zero2 Trench Football Helmet, SC-223-S Facemask Attached, White, Large
Revolutionary new ZERO1 football helmet already in play, said to help dramatically reduce concussions
NFL helmet safety rankings: Seattle startup Vicis tops list again with high-tech head protector – GeekWire
Will the NFL's Blitz for Position-Specific Helmets Pay Off?
NFL at 100: Helmets go high tech in quest for player safety