By definition, an option is not necessary. However, options are available in case you want to take advantage of specific features. You can find all options here: http://shop.fly-air3.com/shop/category/air3-19. Check the accessories page to know more about each option.
A large number of pilots think the only way to have a good readability is to increase the nits (~ brightness) or to use a eInk screen (black and white). The most important factor is the angle of the screen with the look (perpendicular) and not the nits/brightness). Read more details about best brightness setting Read more about How to get the best readability?[…]