Recap: While they may be very expensive and their practicality remains questionable, folding phones are the mobile industry’s current hot topic. Samsung and Huawei look to have the most anticipated products on the way, but some manufacturers, including Sharp, have taken a different approach to the foldable design.

Unlike Samsung’s Galaxy Fold and Huawei’s Mate X, which fold horizontally, the prototype device that Sharp just unveiled closes in on itself vertically, making it more like a traditional phone that can be folded in half.

We’ve already seen a very similar design from Motorola, whose $1,500 Moto Razr concept is also a clamshell-style foldable that can be turned into a very compact size.

The device here features a 6.18-inch, 1440 x 3040 AMOLED screen that’s reportedly undergone 300,000 fold tests—100,000 more than what the Galaxy Fold experienced during its stress testing phase.

Another similarity with the Razr foldable is the notch, which could be the element that puts most people off. Sharp has said, however, that a commercial version of its device won’t be ready for “a few years," by which time notches might have fallen out of fashion and the final design could change.

A recent report on the mobile industry predicted that foldable phones would remain a niche product for several years, and even by 2023 would only have captured 5 percent of the market. We still don’t know how consumers will take to the devices, but these vertical designs appear to be getting more positive responses than the book-style, tablet-sized foldables.