The device has a 4.6-inch screen when used as a phone and can unfold into a tablet with a 7.3-inch screen, Samsung said Wednesday during a demonstration kicking off its Unpacked event in San Francisco. The company said the new phone, called the Galaxy Fold, will be available April 26 and come in four colors: black, blue, silver and green. Users will also be able to customize the color of the folding hinge.

Samsung’s device is not the first foldable-screen phone, but the company’s brand, reach and technological prowess makes it the most advanced folding phone for the mass market. It’s a leap that rivals the category shifts not seen since smartphones took off with a broad audience more than a decade ago.

The larger screen means users can multitask and view three applications at once, the company demonstrated on stage. Users can display the Galaxy Fold like a phone, then open it up to see the larger view via a feature called App Continuity, Samsung said. The company said it’s working with Google on Android and third-party developers to optimize the software and their applications.

The Samsung device includes a new chip and 12 gigabytes of RAM, which is more memory than most laptops. It also has 512 GB of storage, which is the same as the maximum for Apple Inc.’s latest iPhones. The phone includes two batteries — one below each screen — to allow for the folding mechanism to function properly.

The Galaxy Fold has six cameras across the back, front and inside the fold of the phone. DM