Apple on Tuesday announced new iPhone models and the final version of its mobile operating system, iOS 7. But the firm declined to announce expected updates to the iPad, iPad mini, iPod, and Apple TV, perhaps saving those for a separate October event. The new iPhones are available for preorder on September 13 and will begin shipping a week later.

Two new iPhone models were introduced, the iPhone 5C, which is aimed at the lower end of the market, and the new flagship model, the iPhone 5S.

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Many had expected the iPhone 5C to be available for $200 to $300 off-contract, which would have helped Apple shore up its dwindling share of the market's low end. But the company is holding on pricing, with the entry-level 16GB version costing $550 without a contract. For those willing or able to handle a two-year contract, that phone will start at $99, with a 32GB version hitting $199.

For that money, you get a new plastic design that is curiously—one might say suspiciously—similar to the Lumia handsets that Nokia has been selling for the past two years. The iPhone 5C features an "unapologetically plastic" back that comes in five colors: blue, green, pink, yellow, and white. The phone still features a relatively tiny 4" screen and is generally identical to last year's iPhone 5 but with cheaper plastic exterior parts.

The iPhone 5S features the familiar iPhone 5 design but adds a faster A7 microprocessor, a new 8-megapixel camera, and a fingerprint sensor called the TouchID that makes signing in to the phone more secure. It will be priced at $199 for the entry-level 16GB model, $299 for a 32GB version, or $399 for a 64GB version.

Apple also revealed that its next mobile OS, iOS 7, will ship September 18 and be made available to users with newer iPhones, iPads, and iPod touches. It will be free.