Great for those who have existing switches in place that they want to keep. For instance, custom switches or those with fancy wall plate/switch plate covers. This allows you to put a module behind the switch and allow them to act as both smart and dumb switches. Controls two devices in the same time. This is the comparable, dual relay Sonoff product compatible to the Shelly 2.5 and does not offer dimming functionality however other products in the Sonoff lineup do. Other models are available that monitor power consumption, don’t require neutral lines, provide lighting effects, extended energy management features, and more.