November 24 update: At least according to a new patent, OnePlus is now actually working on a foldable phone.

August 12 update: Turns out this "foldable" teaser was meant to promote a 50% off promotion for the OnePlus 9. OnePlus got our attention, but this didn't seem like a great way to do it.

OnePlus posted a suspiciously timed teaser suggesting that they were working on a foldable phone. At the very least, it's a foldable dual-screen phone. And it appears we will see more later today.

An Instagram post and tweet by OnePlus USA shows part of the folded phone and a date of August 11. This could be just a concept phone rather than an actual product, like last year's OnePlus Concept One, but of course we expect it to be a surprise announcement of an all-new OnePlus phone. And it will take place on the same day as Samsung's Galaxy Z Fold 3 reveal.

From the teaser, the OnePlus fold is not a flexible display, but two separate screens that work together. We have seen this approach before with the Microsoft Surface Duo and the optional dual-screen mod of the LG G8X ThinQ. There are advantages to this approach, as flexible displays can be made from tougher materials, but the resulting design can be bulky. [Given that the Galaxy Z Flip 3 is expected to join the Fold 3 and is rumored to launch not one but two foldable phones, it would be hard to steal Samsung's thunder today. Additionally, Samsung is rumored to be launching the Galaxy Watch 4 and Galaxy Buds 2.

However, those tired of seeing Samsung effortlessly hold the title of best folding phone on the market will be glad to see OnePlus, one of Samsung's closest rivals in the Android field, get in on the action.

OnePlus has a rather opportunistic arrangement to make its announcement on the same day that Samsung is holding its Galaxy Unpacked event. The recommended solution to this problem is to open Galaxy Unpacked's live blog in one tab and OnePlus' social media in another. This way, you won't miss any important details from either company's announcements.