Passive NFC Wireless Image Refresh Technology: Utilizes a passive NFC solution, eliminating the need for internal batteries or complex wiring for seamless operation. Wireless Power and Display Refresh: To refresh the display, simply bring an NFC-enabled smartphone or card reader close to the e-ink screen for wireless power and content update. Versatile Use with Hanging Hole: The design includes a hanging hole for easy attachment to accessories like bags or keys, making it ideal for use as a decorative charm with a curved metal frame. Premium Metal Frame: The product features a sleek and durable metal border, combining aesthetic appeal with high durability for long-lasting use. The product features NFC wireless power, 2 grayscale levels, red, yellow, black, and white display colors, a 15s refresh time, 0.135 × 0.135 dot pitch, >170° viewing angle, 200 × 200 resolution, 27.00 × 27.00 mm display size, and 47.84 × 41.28 mm overall dimensions. Rich WiKi Resources: We provide official Wiki resources, please visit our store and click the wiki page to get resources. Waveshare 1.54inch Color NFC E-Ink Display with Red, Yellow, Black, and White, 4 Colors, Battery-Free, Wireless Power & Image Refresh, Silver Border