Oppo has teased a new wireless charging solution that works when a phone is up to 10 cm (3.9 inches) away from a charging pad. The company has shown off its Wireless Air Charging tech in a 30-second clip on its Weibo page to coincide with MWC Shanghai. The clip shows the Oppo X 2021 rollable concept phone, announced in November, charging above the pad, even when held at an angle. The technology offers charging speeds of up to 7.5W, Oppo says.

The Chinese manufacturer is the latest to announce a truly wireless air charging solution, following Xiaomi and Motorola’s teases from earlier this year. Back in January, Xiaomi announced Mi Air Charge Technology, which it says can charge multiple devices at 5W “within a radius of several meters.” The next day, XDA-Developers reported on a demonstration from Motorola which showed one of its phones charging 100 cm (40 inches) away from a charger.

At 10 cm, the range of Oppo’s technology is more limited than Xiaomi’s competitor, Android Authority notes. The video’s presenter makes a very deliberate effort to hold the phone directly above the charging mat. However, the charging is shown working even when the phone is slightly tilted above the wireless charger, and while playing back a video.

Distinctions like this are academic right now since none of these technologies have been released in commercial products. Xiaomi has confirmed its technology won’t be ready to release this year, and the rollable phone that Oppo used for its demonstration also doesn’t have an official release date.

As well as developing wireless chargers that work over longer distances, manufacturers are also working to make standard wireless charging faster. Xiaomi is developing an 80W wireless charging solution, which it announced just months after Oppo revealed its own 65W wireless charging tech.

Update February 23rd, 6:53AM ET: Updated with official name of charging solution, and more details.