Shown in the above photo is the Elgato Multi Mount Smartphone Holder. The dummy phone is for demonstration purposes only (not included), and other Elgato accessories are each sold separately.
Here is some general information about Elgato Multi Mount Smartphone Holder:
Elgato Multi Mount Smartphone Holder
Max Width
8.5 cm / 3.35 in
Materials
Steel, Supple Rubber
Elgato Multi Mount Smartphone Holder - Setup
Here is a pictorial guide of the setup of Elgato Multi Mount Smartphone Holder.