HoloLens Clicker is an accessory that comes along with HoloLens. It connects to the HoloLens using Bluetooth and allows a user to click and scroll with minimal hand motion. You can consider this as a replacement for Air Tap gestures where, instead of using hand gestures, you can use the Clicker. When an object is gazed, you can press the button on the Clicker, which will execute the Air Tap command for the selected object.
HoloLens Clicker