DJI's most advanced technology comes together in the Inspire 1, an easy to use, all-in-one flying platform that empowers you to create the unforgettable. Never before has such power been put into a ready-to-fly system that anyone can fly. Optical Flow: Accurate position holding even indoors or when GPS is unavailable. Full-Featured App: Take complete control of your camera and flight system with a comprehensive mobile app. Source: http://www.dji.com/product/inspire-1