Like its counterpart, the Shelly Plus i4, the Shelly Plus i4 4-Input DC controller is an input reader device, meaning it can communicate with and coordinate multiple Shelly relays and switches around your home to create sophisticated, synchronised scenes or schedules; simultaneously adjust lighting, heating, curtains, fans, and any other appliance with an installed Shelly device at the touch of a button. The Shelly Plus i4 DC, unlike the Shelly Plus i4, is engineered specifically for lower-voltage DC currents of 5-24V, and is small enough to be installed behind any multi-button switch like the Shelly Wall Switch.