Friends of Hue - The Niko dimmer switch for the Hue system communicates wirelessly (via the Zigbee® protocol) with the Philips Hue bridge V2.
The Niko dimmer switch for the Hue system works without batteries. It uses kinetic energy. That means that, every time you press the switch, this energy is saved and used to operate the controls. Therefore, you never need to replace a battery.