Passive NFC wireless image scanning technology,Adopt passive NFC solution, no built-in battery, no need for complicated wiring. When you need to refresh the display, you can use a smartphone or card reader with NFC function.Move close to the ink screen for wireless power supply and refresh the displayed content. Reserved hanging hole, lanyard included,Can be used for bag ornaments, key ornaments, etc. Application scenarios,Suitable for mobile phone key pendants, business cards, decorations, etc. Power supply method:NFC wireless power Grayscale:2 Display color:Red, yellow, black, white Refresh time:15s (excluding data transmission time) point distance:0.135 x 0.135 Viewing angle: 170 resolution:200 x 200 display size:27.00 x 27.00mm (The product printed words depending on the batch, but this does not affect use) Color: As Shown Material: LCD Package Contents: 1 x 1.54inch NFC e-Paper Display Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.