Smartphones, for all their flaws, are a wonder of modern technology, packing in powerful specs and features and giving us all supercomputers in our pockets. With the Samsung Galaxy S25 about to be announced but with rumours suggesting the phones will barely differ from the S24 series, you might rightly be wondering how phones can evolve to be noticeably better than they already are.

One major aspect is design, and smartphone maker Oppo has just teased its next flagship device, claiming it to be “the world’s thinnest folding flagship” (as spotted by The Verge). That’s according to official images posted on social media site Weibo by Oppo’s Zhou Yibao, who is product manager for the firm’s Find range of phones. He refers to the teased device as the Oppo Find N5, which looks set to be Oppo’s next book-style foldable Android phone.

In two images (see above and below) the Find N5 is photographed next to an iPhone 16 Pro Max to show just how thin it really is. It is unfolded but is barely thicker than the USB-C port on the bottom.

“Thinness is not the limit of Find N5, but the limit of the charging port”, Zhou writes (translated from Chinese). He doesn’t state exactly how thick the Find N5 is, but the images clearly show it is dramatically thinner than the 8.25mm thick iPhone. It reminds us of the ill-fated Microsoft Surface Duo and Surface Duo 2, the phones that had two separate screens that folded on a hinge. The former was so thin when unfolded at 4.8mm that the plastic around the USB-C port cracked on many models.

Oppo will hopefully not have used such flimsy material on the Find N5, which will of course be twice as thick when folded shut and will have one folding screen on the inside rather than Microsoft’s two screen design. Other images shared show the phone as thick as four stacked credit cards and two Chinese yuan coins.

We reviewed the world’s current thinnest folding phone, the Honor Magic V3, back in October. That device is 4.35mm thick when unfolded, so Oppo claims it has those dimensions beat. Thinness does not necessarily equal a superlative phone, but the V3 is a joy to use thanks to the fact it feels like a regular phone when closed and you can use the normal-phone-sized outside display.

Oppo recently released the excellent Find X8 Pro slab-style phone in the UK, but it did not officially launch its last foldable, the Find N3, on these shores. As Oppo is owned by the same company as OnePlus, it often shares designs with its stablemate, so Brits were able to buy the OnePlus Open, which was practically the same hardware. We can assume the Find N5 will be the same design as the rumoured OnePlus Open 2, which is expected to be announced for the UK market at some point this year.

Though the OnePlus Open was a great foldable, Honor’s better design now makes it feel quite chunky. In the battle to give foldables mainstream appeal, it seems as though manufacturers are concentrating on thinness this year.

In another post on Weibo, Zhou touted the improved water resistance of the Find N5.

“This time, the waterproof performance of OPPO Find N5 has been fully upgraded,” he said. “It should be the only folding flagship on the market that supports IPX6, IPX8, and IPX9 full-level waterproof.”

The ‘X’ here means it won’t be dustproof, but the other ratings up to IPX9 mean it is able to survive both being fully submerged in water and also from high pressure jets. OnePlus showed off the IP69 rating on its OnePlus 13 by putting it in a dishwasher, but we don’t recommend you do the same.

The Find N5 is set to launch in China next month, but Express.co.uk is waiting patiently for the OnePlus Open 2 in the hope it will be unveiled in the near future.