This product is the double frame of Shelly Wall Switch product series - with elegant black glass front.
The frame needs to be used together with the wall switches and a compatible relay. 
Size: 150mm x 80mm x 10mm

Shelly's new 2022 product is the Shelly switch series, with 1 / 2 / 4 button switches and compatible 1 / 2 / 3 (single / double / triple) frames. The product line is also available with elegant white and black glass front.
The switch is not a fully functional switch, it is just a button with 1, 2 or 4 buttons. It's a front panel equipped with a microswitch, which comes with an adapter for a Shelly switch. A Shelly WiFi smart relay needs to be inserted into the relay holder adapter and wires should be connected together.

A relay + switch with relay adapterr + a frame is together a fully functional product.

The frame and the switch is sold separately. (And the Shelly smart relay is not part of the product, it can be ordered separately.)

Relay adapter are available for Shelly 1, Shelly 1PM, Shelly 2.5, Shelly Plus 1, Shelly Plus 1PM, Shelly Plus 2PM, Shelly Plus i4 Shelly smart devices, and adapters are provided together with the switch buttons. 

It can be switched in the same way as conventional switches
Shelly wall switches work just as traditional wall switches, but they can be also controlled via the relay's Wi-Fi connection through your home automation system and from a smartphone app.

Easier wiring and connection
With the Shelly light switch system, the wiring and connection of the Shelly smart relay becomes much easier, as the wiring between the relay and the switch can be conveniently done on the table, and then the relay can be wired with the remaining wires in the same simple way as a traditional switch.

The smallest solution
A combination of a Shelly relay, a switch and a frame requires the smallest possible space in the wall junction box. If there is not enough space in the wall box or the wall is too thin, then the Shelly switch is the best choice for a smart switch.