Apple on Tuesday unveiled its highly anticipated iPhone 17 Air, which starts at $999. The company debuted the 5.6mm-thick phone at its fall keynote at Apple Park in Cupertino, California. The phone has a 6.5-inch display and a titanium frame for a durable, lightweight build. Ceramic shield material covers the front and back. Like the baseline iPhone 17, the 17 Air has a 120Hz variable refresh rate, meaning it supports an always-on display, so you can see your notifications without waking the screen. It also has 3,000 nits peak brightness. The phone packs an A19 Pro chip. It also has Apple's N1 chip for Wi-Fi 7 and Bluetooth 6, as well as a faster and more efficient version of its in-house 5G modem, the C1X, which is an update to the C1 modem it debuted on the iPhone 16E earlier this year. Apple on Tuesday called the Air the "most power-efficient iPhone we have ever made," and says it has all-day battery life -- though you can buy a MagSafe battery that Apple is already touting to extend that life. Adaptive Power in iOS 26 can also help conserve battery life by automatically adjusting your iPhone's performance based on how you're using it at that moment, according to Apple. On the back, the iPhone 17 Air has a 48-megapixel fusion camera, which allows for 2x telephoto pictures. It also has Apple's new Center Stage selfie camera that works in both a landscape and portrait orientation. Preorders for the iPhone 17 Air and the entire iPhone 17 lineup begin on Friday, with availability starting on Sept. 19.