In recent years the NFL has continued making a push for player safety as much as possible in football. This year, that continues with the requirement for players to wear Guardian Caps along with their helmets for full contact portions of training camp.
The Guardian Caps are soft shell pads that are attached to the outside of the helmet and were developed at least partially using a Grant from the NFL. They will be in use when full contact begins at training camp and will be required until after the second preseason game at which point they will be recommended instead.