San Francisco 49ers Riddell NFL Authentic Revolution Pro Line Full Size Helmet. The most significant design change in football helmets in over twenty years. The Revolution helmet was designed after a four-year-study to address the causes of mild traumatic brain injury. Extended mandible (jaw area) protection increased side padding integrated facemask attachment system weight balance redistribution Elliptical Air Vents Now available as an NFL-licensed on field authentic helmet. The striking shape of the future.