Gizmochina
Credit: OPPO
OPPO showcased how the Wireless Air Charge Technology works on devices via a demo video. In the video, you can see the device used is the OPPO X 2021 rollable smartphone. Just like Xiaomi, OPPO tech seems to be true wireless charging as the device continues to charge even after lifting it from the charging mat a few centimeters above.
At the MWC Shanghai Booth Number N2-E40, it explained that the Wireless Air Charging tech can go up to 7.5W of charging power. As for the distance, OPPO says that a user can take the device up to 10cm distance from the charging mat to continue charging.