Some of the impact may be blunted because there are three different varieties of 5G.

It could be the first major case redesign since 2018 and the expectation that Apples new iPhones will support 5G cellular networks have investors hoping for a big upgrade cycle.

We expect this falls launch to be the most significant iPhone event in years, Morgan Stanley analyst Katy Huberty wrote this week.

VIDEO 3:53 03:53 Recodes Kara Swisher: This is Apples most important iPhone event in years Squawk Alley On Tuesday, Apple is holding a launch event where it will reveal this years iPhone lineup.

In most years, Apple announces its iPhones in September, and they go on sale shortly after that.

Apple instead released new Apple Watches last month and pushed the iPhone announcement to October.

The delay is an outgrowth of the Covid-19 pandemic, which disrupted electronics manufacturing and forced most Apple employees to work from home.

It is expected to include the first major exterior redesign since 2017, when Apple released the iPhone X with facial recognition.

This years models will feature iPad-like edges with flatter sides, compared with the gently curving sides of the current iPhones.

Apple is also expected to release four separate iPhones at different screen sizes and prices -- a much wider range of devices than in the past.

Finally, at least some new iPhones will support 5G cellular networks, which promise faster download times (although the networks arent fully built out yet in the U.S., which could disappoint some users.) The last time Apple made such big changes to the iPhone was 2014, when the iPhone 6 came out with bigger screens and two different sizes.

That remained the annual unit sales record until Apple stopped reporting unit sales in 2018.

VIDEO 6:04 06:04 Investors on what a new iPhone could do for Apples stock price Halftime Report So this years changes have investors and analysts predicting a big upgrade cycle that will make Apple an even more valuable company.

We expect this falls launch to be the most significant iPhone event in years, Morgan Stanley analyst Katy Huberty wrote in a note this week.

Shes forecasting Apple to ship about 220 million iPhones in its fiscal 2021, which would be up 22 year-over-year according to the Morgan Stanley model.

Four iPhones, including a new iPhone Mini Morgan Stanley analysts are expecting an iPhone lineup of 4 new devices, including: iPhone 12 Mini, a new device with a 5.4-inch screen.

Phone 12 Pro Max, which would have the largest screen ever at 6.7 inches (todays iPhone 11 Pro Max tops out at 6.5 inches) Morgan Stanleys expectations are based on information from Apples supply chain of manufacturers in China.

That means the actual names, which are controlled by Apple product marketing in California, may end up being different.

Four models would be a dramatic expansion of its lineup, with both a new smaller option and a larger high-end option, giving consumers more choices and potentially spurring people to upgrade.

The phones are expected to be visually different from past years models, giving users another reason to upgrade.

Currently, Apple sells the 699 iPhone 11 with a 6.1-inch screen, a 999 iPhone 11 Pro with a 5.8-inch screen, and a 1099 iPhone 11 Pro Max with a 6.5-inch screen.

Apple may continue selling these models -- typically, it knocks 100 off the price of last years models and keeps them on store shelves.

Different kinds of 5G Apples tagline for the event is Hi Speed, a reference to the faster cellular speeds promised by 5G phones.

Investors and analysts have hoped for years that a 5G iPhone would represent a major upgrade and spur a big wave of sales not only for phone makers like Apple, but also for chip-makers like Qualcomm and carriers like Verizon and T-Mobile, which have bet big on 5G.

For instance, ATT Communications CEO Jeff McElfresh told CNBC in September that he did not believe it would be a massive event.

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