The Cortana Button offers an alternative to the Hey Cortana feature, which actively listens for users to call out the prompt 'Hey Cortana' to begin voice interactions, and adds to battery drain on mobile devices. The new accessory instead connects to a device via Bluetooth 4.0 LE (low energy), with a range of up to 40 feet, and when you need to interact with Cortana, you simply push the button, opening the assistant on the Windows 10 phone or PC. The device is ,priced at $22.99, which includes a mount to attach it to various places as it suggests. The company also promises "amazingly long battery life of up to 2 years" from the device, which you can see in action in the video below: