You know what this is. The phone millions and millions and people will own over the next twelve months. It looks like an iPhone 6, and acts like an iPhone 6. But it’s not. As the designated “S” upgrade, Apple’s new device has a few new tricks up its sleeve, and I’m not talking about the improved camera or new specs.

Ever heard of 3D Touch? You will.

While most of Apple’s “toc” upgrades simply introduce better specs, this year’s update is all about 3D Touch, which itself is inspired by the Apple Watch’s Force Touch. The technology essentially determines between taps, presses and hard presses, intelligently understanding pressure and delivering context. In iOS 9, Apple calls this “peak” and “pop.”

Peak will let users do things like quickly glance at important information and take shortcuts around the OS. Pop, meanwhile, is what happens after Peak. If you’re Peaking at a Safari link, for example, all you have to do is press harder and you’ll jump fully into that link. You can do this all around Apple’s OS, though it isn’t quite supported by third-party developers just yet, which is really what will determine the technology’s success or not.

By all accounts, early reviews peg 3D Touch as the iPhone’s killer feature for years to come. This isn’t just a long press you perform in Android; 3D Touch can discern between different pressure and adapt the UI based on apps and links and pictures. It’s a clever addition, and should make navigating iOS a much better experience.

Of course, we haven’t yet made up our mind about whether 3D Touch is the bee’s knees. For now, check out our unboxing to get a quick idea of how things work. We’ll have a full demo of the technology soon.