Samsung has unveiled its much-anticipated folding phone at its developers conference in San Francisco.
The device does not have a name yet but the flexible mobile screen technology is called the Infinity Flex Display.
The company hopes to mass produce the phone - which unfolds from a compact smartphone to a 7.3-inch tablet - "in the coming months".
There is also a secondary screen that can be used when the phone is in a compact mode.
Samsung is facing tough competition to deliver its foldable smartphone, with Royale Corporation, a California-based tech company, unveiling its challenger in Beijing last week.
Samsung's device is expected to cost more than £1,000 when it is launched in 2019.
Foldable phones hold out the promise of allowing consumers to do more complex work that would normally be done on a tablet or laptop.
It will require developers to tweak apps to make sure they run smoothly when the phone folds out into tablet form.
Dave Burke, vice president of engineering for Android, said: "It's an exciting concept and we expect to see foldable products from several Android manufacturers.
"In fact, we're already working closely with Samsung on a new device they plan to launch early next year."