As expectedApple (NASDAQ:AAPL) just sent out invites for a product-unveiling event. Every fall, the tech giant announces new iPhones and other devices -- and this year is no exception. "Gather round," reads invitations sent to the press on Thursday, likely referring to Apple's new ring-shaped campus, where the event will take place. 

The "Apple special event" will be held on Wednesday, Sept. 12 at 10:00 a.m. PDT in the company's new Steve Jobs Theater at Apple's new headquarters in Cupertino, California. The closely watched annual event will likely feature several new product launches, including new versions of iPhones, an Apple Watch Series 4, and possibly more.

An iPhone, Apple Watch, and AirPods charging wirelessly

Image source: Apple.

Building on the iPhone X

While most of the products Apple launches at its fall events vary from year to year, there's one product that's announced every time: the iPhone. So as usual, this is the update investors can expect with near certainty.

Apple is widely expected to launch three new iPhones this year -- all of which build on the company's popular edge-to-edge display design featured on the iPhone X. This means all three phones will likely have the notch at the top of the display and no home button. In addition, all three of the new iPhones are expected to sport Apple's new A12 processors.

But pricing and size for each of the three devices is expected to vary. Starting prices for the new models are believed to range from as low as $700 to as high as $1,000. The smallest version of the new iPhone is expected to have a 5.8-inch display -- the same size as the current iPhone X. But the other two versions are expected to have 6.1-inch and 6.5-inch displays.

Beyond iPhone

Of course, Apple's new iPhones matter more to the company's business than any other product. iPhone sales account for 62% of Apple's trailing-12-month revenue. But investors likely are equally as interested in whether Apple can keep up its momentum in its fast-growing "other products" segment, which includes sales of the hot-selling Apple Watch and AirPods.

In Apple's most recent quarter, other products revenue jumped 37% year over year, taking the lead as the company's fastest-growing segment. This growth was fueled mostly by Apple Watch and AirPods, according to management in the company's fiscal third-quarter earnings call. During the period, Apple Watch revenue was up about 45% year over year, and AirPods continued to be "a runaway success," according to Apple CFO Luca Maestri. "[W]e've been selling them as fast as we can make them since their launch a year and a half ago," Maestri added.

Apple is expected to debut a new version of the Apple Watch, which is rumored to feature a larger display than previous versions, thanks to its purported narrower bezel sizes.

Other than new iPhones and an Apple Watch Series 4, other potential products could include refreshed iPads and Macs. Of course, a total surprise is always possible, too.

Daniel Sparks owns shares of Apple. The Motley Fool owns shares of and recommends Apple. The Motley Fool has the following options: long January 2020 $150 calls on Apple and short January 2020 $155 calls on Apple. The Motley Fool has a disclosure policy.