The Smart Switch is a battery-operated, wireless switch with up to four different functions that can control all SG smart devices. The functions are programmed via the SG app "SG Smart." This allows you to activate lighting scenarios or control individual dimmers, dimmer groups, or even the entire room lighting. The battery life is between 2 to 5 years, depending on usage. It uses standard button cells that can be replaced individually. The Smart Switch is suitable for surface-mounted and flush-mounted installation (including on glass) and can also be used as a remote control. It is available as a complete switch with two unmarked buttons or as a complete switch with four buttons featuring common labels such as home/away, daytime/nighttime. Battery life is 2 to 5 years. Battery: CR2450 3V.