At Apple’s press event on Sept. 7, the company unveiled a new Jet Black iPhone 7. But it might have a design consideration customers should know about before buying.

After Apple’s AAPL event on Wednesday, it published a dedicated iPhone 7 page showing all five color versions customers can choose when the iPhone 7 and iPhone 7 Plus are available for pre-order on Friday. On its Jet Black model listing, Apple includes a footnote that might give some pause.

“The high-gloss finish of the Jet Black iPhone 7 is achieved through a precision nine-step anodization and polishing process,” Apple writes. “Its surface is equally as hard as other anodized Apple products; however, its high shine may show fine micro-abrasions with use.”

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In other words, the iPhone 7 that offers the most enhanced design over its predecessors—and arguably the most attractive look—is subject to scratches and other problems that could affect its finish. And in order to address that, Apple went so far as to suggest customers consider a case.

“If you are concerned about this, we suggest you use one of the many cases available to protect your iPhone,” Apple writes.

The Jet Black iPhone was one of the focal points in Apple’s iPhone 7 presentation on Wednesday. The company shared videos showcasing the device and talk about the time and effort it takes to deliver its polished design. On its website, Apple displays the iPhone 7’s Jet Black version first.

Apple’s revelation, however, could give some customers who are looking to get their hands on the updated design some pause. While it’s undoubtedly an attractive product, over time, its attraction might give way to some concerns about its ability to hold up against too much use. If such concerns are present, customers will either need to decide to opt for another model that doesn’t come with the same manufacturing and polishing process and therefore doesn’t make it as likely to suffer “micro-abrasions,” or opt for a case.

The trouble with a case is that it shrouds the iPhone’s design. In addition to announcing component improvements on Wednesday, Apple spent considerable time talking about its design achievements. In nearly all of the cases currently on the market or launching soon for iPhone 7 models, the smartphone is fully encased and its design is covered by the case’s design. The Jet Black’s beauty is gone once a case is slapped on.

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For some would-be iPhone customers, Apple’s sales pitch on the Jet Black version during its event was enough to make them want it. But whether the warning on Apple’s site—which wasn’t discussed during the event—will change users’ minds remains to be seen.

The iPhone 7 and iPhone 7 Plus will be available for pre-order starting on Friday. They’ll launch to Apple and carrier stores, as well as third-party retailers, on Sept. 16.