If you’re used to the vertical flip opening of phones like the Motorola Razr, or still fondly remember snapping your vintage not-so-smart cellphone open and shut, think different. The just-announced folding iPhone Duo opens horizontally, like a book, and its size and fold direction make it reminiscent of a paper passport. The much-anticipated phone was revealed Wednesday at Apple’s latest event.

While it wasn’t confirmed until this week, the folding phone was the worst-kept secret in tech, with hundreds of articles reporting that it was on the way. And it joins a crowded field of foldable phones, with key players including Samsung, Google and Motorola, and Chinese brands like Honor, Oppo and Huawei. But as CNET’s Abrar Al-Heeti notes, Apple’s entry into the fray is expected to nudge foldable phone designs forward.

Al-Heeti notes that the iPhone Duo is compact, and Apple says it’s the thinnest iPhone ever when opened. The phone has a 7.6-inch display on the inside, a 5.4-inch outer display, and will come in two colors, star white and night sky.

Foldable phones typically have visible creases where the phones fold in half. CNET Director of Content Patrick Holland notes that this is an issue preventing some shoppers from buying foldable phones, but he says the crease is “nearly nonexistent” on the iPhone Duo. He says it will be interesting to see whether the crease becomes more pronounced as the foldable phone ages, as it has with all other foldable phones.

CNET editor Gael Fashingbauer Cooper, a journalist and pop-culture junkie, is co-author of “Whatever Happened to Pudding Pops? The Lost Toys, Tastes and Trends of the ’70s and ’80s,” as well as “The Totally Sweet ’90s.” She’s been a journalist since 1989, working at Mpls.St.Paul Magazine, Twin Cities Sidewalk, the Minneapolis Star Tribune, and NBC News Digital. She’s Gen X in birthdate, word and deed. If Marathon candy bars ever come back, she’ll be first in line.

See full bio