The iPhone SE (iPhone Special Edition) is a smartphone designed and marketed by Apple Inc. as part of the iPhone series of devices. It was unveiled on March 21, 2016, at Apple's Cupertino headquarters and was released on March 31, 2016. The iPhone SE serves as a replacement for the iPhone 5S: it maintains a 4-inch screen size and nearly identical design to the 5S, but includes selected hardware upgrades from larger iPhone 6S model, including its updated processor, rear camera, and support for iOS 9 software features such as Apple Pay, always-on Siri activation, and Live Photos. Reception to the iPhone SE was critically positive, noting its familiar form factor and design, improved hardware over previous iPhone models with 4-inch screens, and its overall performance and battery life.