The Smart Switch is a battery-operated, wireless switch with up to four different functions that can be used to control all SG smart devices. The functions are programmed using the SG app SG Smart. This can be used to activate lighting scenarios or control individual dimmers or dimmer groups or even the entire room lighting. The battery life is 2-5 years, depending on use. These are standard button cells that can be replaced individually. The Smart Switch is suitable for surface and flush mounting (also on glass) and can also be used as a remote control. A complete switch with two rockers (unmarked) or a complete switch with four rockers with the most common markings such as home/away, day/night. The battery life is 2-5 years. Battery: CR2450 3V.