With Apple's September event less than a week away, it won't be long before we see the iPhone 15 series for the first time. According to a steady stream of rumors, this generation will bring yet another update to most models, which is bad news for those considering trading in their iPhone 14 or earlier models.

However, this high-end option, the iPhone 15 Pro, surpasses the standard iPhone 15 with a few design tweaks that should be enough to convince users who are hesitant to upgrade. This is based on leaks we've seen so far and a report this week from Bloomberg's Mark Gurman detailing Apple's plans.

Apple's "Wonderlust" showcase will begin on September 12 at 10:00 AM Pacific Standard Time. Check out our guide on how to watch the event, including where to watch the live stream and what to expect. There, the iPhone maker is expected to show off its most anticipated new products, including the next-generation smartphone line, Apple Watch Series 9, Apple Watch Ultra 2, changes in iOS 17, and the latest AirPods.

One of the biggest design changes separating the standard iPhone 15 and 15 Plus from the Pro models is the chassis material: the 15 Pro and 15 Pro Max will replace the traditional stainless steel with a more durable and lighter titanium frame, while the regular iPhone 15 and 15 Plus will use an aluminum chassis.

This is a long-rumored feature for the iPhone, as Apple is expected to eliminate stainless steel entirely from its iPhone lineup. A titanium chassis could lead to a stronger and lighter Pro iPhone. Some sources calculate that the titanium iPhone 15 Pro will weigh 6.74 ounces.

In a report this week, Garman said the titanium chassis will make the iPhone 15 Pro and 15 Pro Max "more durable and about 10% lighter" than their predecessors, citing unnamed sources at Apple who know of the company's plans.

Another bold change rumored for the iPhone 15 Pro and Pro Max is that Apple will eliminate the long-standing mute switch and replace it with a solid-state action button similar to the one on the Apple Watch Ultra.

This button will, of course, turn the phone's ringtone on and off, just like the mute switch. However, with the iOS "Shortcuts" app, you can also program this button to perform other useful functions or execute a series of commands.

Some of the shortcuts mentioned by Gurman's sources include silencing the phone, switching focus mode, activating the flashlight, starting the camera, starting voice recording, opening a Siri shortcut, pulling out the digital magnifying glass, and opening accessibility settings.

Smartphone makers have been gradually shaving off bezels over the years, and Apple is no exception. in the iPhone 15 Pro, the bezel surrounding the display will be significantly slimmed down to just 1.55 mm, compared to 2.1 mm on the current iPhone 14 Pro. The iPhone 15 Pro could be slimmer than the current iPhone 14 Pro's 2.1 mm bezel.

To achieve the slimmer bezel, Gurman reports that Apple has adopted a new manufacturing process called LIPO (low injection pressure over molding). We first saw Apple use LIPO on the Apple Watch Series 7 to shave off the bezel to increase the overall display without increasing the size of the casing. Rumor has it that Apple plans to use this technology in iPad models as well.

The iPhone 15 Pro and 15 Pro Max will reportedly feature Apple's A17 Bionic chip, which will significantly improve performance and battery life. The iPhone 15 and 15 Plus, on the other hand, will feature the slower A16 chip from last year's iPhone 14 Pro and 14 Pro Max.

"The high-end phones will have a performance edge, maintaining Apple's approach of recent years," Garman explained. "The processor will make these models more agile, but the biggest enhancement is in battery life savings. "

Apple has confirmed that future iPhones will change from its own Lightning charging port to USB-C, in line with new European Union regulations. We expect to see the first of these in the iPhone 15 series, where it has been suggested that all four models will feature USB-C charging ports. However, the Pro model could gain an additional advantage.

For starters, the iPhone 15 Pro models are said to feature faster charging speeds, up to 35W. In contrast, the iPhone 14 Pro Max is limited to 27W charging, while the iPhone 14 is limited to 20W.

Rumors also suggest that the iPhone 15 Pro and Pro Max will upgrade to USB 3.2, with 20 GBps data transfer speeds as standard, and a Thunderbolt 3 connection. The iPhone 15 and 15 Plus, on the other hand, will remain USB 2.0, with the same 480 Mbps data transfer rate as Apple's Lightning port and the entry-level iPad 10.

Support for Thunderbolt 3 is particularly promising, and the upgrade may allow the iPhone 15 Pro to output 4K video to an external screen. A more advanced version of the USB standard should also enhance support for external accessories, which together have the opportunity to turn the iPhone 15 Pro and Pro Max into full-fledged productivity devices.