*** Please Note: This device includes an adapter for seamless integration with your home's pre-existing wall frames. This model includes an adapter for Gira and Merten brand wall frames. The Shelly BLU Wall Switch 4 connects to other Shelly devices on the network through BLE (Bluetooth) technology and contains four buttons, each of which supports multi-click (single, double, triple and long-press clicks) for a total of 16 possible triggers. Unlike Shelly's other wall switches, the Shelly BLU Wall Switch 4 requires no wiring and does not contain a bracket for a Shelly device on the back; instead, this switch contains built-in Bluetooth technology, and be configured through the web interface to wirelessly trigger individual appliances, multiple Shelly devices, or synchronised Smart Scenes.