E-Ink Display – Uses low-power electronic ink technology to display static images, notifications, or custom designs without draining much battery.NFC Connectivity – Allows data transfer between the phone and the case without needing an external power source.Customizable Content – Users can update the display via an app or an NFC-enabled phone by simply tapping.Battery-Free Operation – Many designs rely on the phone’s NFC energy or require minimal power due to E-Ink’s efficiency.Personalization – Can showcase QR codes, business cards, reminders, or unique wallpapers that stay visible even when the phone is off.