With the Apple iPhone Duo, you get both a small device and a large screen, because you can open and close this device. Folded open, you have a large, 7.6-inch screen with the right proportions for videos and series. This is almost as large as the iPad mini screen. Close the screen again and you have a small device that easily fits in your pocket. On the small, 5.4-inch screen at the front, you can check messages and scroll through social media without having to open your iPhone. Buy your iPhone Duo as separate device, so without phone plan. If you trade in your old smartphone, you get a discount on your new Duo.