iPhone 15 Pro models could feature solid-state power and volume buttons, according to Apple analyst Ming-Chi Kuo.

Kuo has explained in a tweet that the volume and power buttons on next year’s two high-end iPhone models could adopt a solid-state design, similar to the iPhone 7’s home button, replacing a physically pressed mechanical button design.

Apple uses a similar method for its Mac trackpads, which they do not physically move and simply mimic the sensation of being pressed with small vibrations.

The new iPhones will feature additional Taptic Engines on the inner left and right sides to provide feedback to users, making it appear as if they are pressing physical buttons. The change means that the number of Taptic Engines in each iPhone will increase from one to three.

Apple was rumored to be planning to switch the Apple Watch to solid-state buttons several years ago, but the change never happened. At the time, it was said that solid-state buttons would improve water resistance and take up less internal space, but it’s not clear if that would be the case for the iPhone, as enough space would be needed for two more Taptic Engines.

In an additional thread, Kuo said that “The buttonless design and the move to USB-C are two of the biggest updates to the iPhone 15.”