The NFL is rolling out new helmets to protect players from violent hits and concussions. The helmets have evolved over the years with newest models customized based on the player’s position. NBC News’ Sam Brock shows us how they work. The NFL is rolling out new helmets to protect players from violent hits and concussions. The helmets have evolved over the years with newest models customized based on the player’s position. NBC News’ Sam Brock shows us how they work. NBC News Science