AirPods contain a proprietary Apple W1 SoC which helps optimize battery use and processes the Bluetooth 4. 2 connection as well as audio. The additional connectivity functions of the W1 requires devices running iOS 10, macOS Sierra, watchOS 3, or later. They can also function as standard Bluetooth headphones when connected to any device that supports Bluetooth 4. 0 or higher, including Android devices. There are two microphones in each AirPod, one at ear level, facing outward, and another at the bottom of the stem.