【New technology application】NFC technology is used to transmit display content to the ink screen of the mobile phone case with low power consumption. After the transmission is completed, no energy is consumed. Even if the mobile phone is turned off or the mobile phone case is removed, the image can be displayed permanently. 【APP is easy to use】Search the APP "Ink Show", download it to your mobile phone, open the APP, and you can freely edit and transfer pictures and text. The APP is very simple to use.The device requires IOS15 or above version. 【Good Points】The reason why choose the ink screen as the display is because its display does not require continuous power supply, does not generate heat, radiation-free,and can be displayed for a long time ,wireless transmission is faster using NFC for ink screen. 【Shortcomings】However,we hope you can understand the shortcomings of the ink screen(Similar products that already exist or will be available in the future).The ink screen we use is a black, white and red three-color screen,it can display simple black and white pictures better, obviously. , it cannot compare the color，Pixel and clarity with LCD screens. If you saw some ink screens display the same pictures as LCD screens, it is untrue. 【Classic appearance】The phone case support cast image on phone case,you can DIY choose picture.Can use as a surprise gift for families,father,mother,friends in some special day,such like mother or father's day gift.Please choose the correct model to fit your phone. The phone case is easy to disassemble and assemble, with sophisticated materials and accurate dimensions.