Will Smart Ink Screen Magnetic Card Holder work with iPhone Air?

Yes, generic magnetic E-Ink card holders and phone wallets designed with MagSafe compatibility will physically attach to an iPhone Air using built-in magnets. However, you should keep a few usability details in mind: 

• Magnetic Alignment: Standard MagSafe card holders and NFC-powered E-Ink wallets attach to the back of the phone via integrated magnets. Because the iPhone Air has a slim profile and specific rear layout (such as horizontal camera placement), some third-party accessories may feel slightly misaligned, fit awkwardly, or require a MagSafe-compatible case. 
• NFC & Ink Screen Functionality: Smart ink screen card holders use NFC signals from your phone to update the E-Ink display without a battery. This data transfer and image updating will generally work as long as the internal NFC coil lines up with the back of the iPhone Air. 
• Ergonomic & Stand Features: Many of these units include built-in kickstands or ergonomic grips that work independently once snapped onto the rear magnetic ring. 

A Google Search suggested some, but not all will work an iPhone Air. What it suggested and I would encourage you to do is check with the manufacturer of the specific one you want to use to see if it is indeed compatible with the Air.