1,Adopts new passive near field communication technology, such 2.13-inch electronic ink screen has no need of built-in battery power consumption, no trouble of battery life. 2,Supports no battery environmental protection and energy saving and simple operation of mobile APP, this screen daopts new passive near field communication technology wireless transmission, which is beautiful and thin with high-quality ABS shell. 3,To work stably, this e-ink screen keeps new passive near field communication wireless brushing technology adopting passive near field communication scheme, which is no need for built-in battery and no cumbersome wiring. 4,E-ink display installation is simple, and its quality is guaranteed, you can use it with confidence. 5,When you need to refresh the display, you can use near field communication enabled smartphones or card readers near this product to wirelessly power and refresh the display content. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-Minnanxin