Amazon quietly updated the camera search on its iOS app with a new “Part Finder,” which lets you search for specific nuts and bolts that you might need more of, but need help identifying. If Amazon’s AR tech can figure out what it is, the app will help you easily buy more of the random screw you’re searching for.

To use Part Finder, iPhone users can open Amazon’s app and tap on the camera beside the search bar. Select Part Finder, which has a screw as its icon. Things get a bit more complicated from there, as you’ll have to perfectly align the part you’re looking at above a penny and tilt your phone until it’s centered, all on a white surface. (I used a piece of paper as my surface, so that part isn’t so difficult.) It took me a little under 10 tries to get the right angle and close-up view of a screw for the app to correctly identify the part.

Part Finder uses the AR capabilities of the iPhone camera to measure the depth and width of the part, and leaves other aspects of identification — like the head style and drive type — to you. Now, I’m not sure anyone should be trusting this tool for mission-critical items or repairs. Taking the mystery bit to your local hardware store might be a better option in that case. But seeing whether Amazon can successfully identify it is a fun trick.

Interestingly enough, Amazon acquired a visual recognition company in 2016 called PartPic, which specialized in identifying small parts. Part Finder is likely the integration of PartPic on the Amazon app.

Amazon says Part Finder currently works for fasteners, meaning screws, nuts, bolts, and washers, but the feature will expand to include other replacement parts soon. The feature is currently only on iOS, and there’s no word on when it will arrive on Android.