This is a simple enclosure to prevent accidental access to the mains contacts of the Shelly 2.5 dual relay switch.
It includes an interchangeable cable clamp to accommodate different cable sizes.
3d model available here -
https://cad.onshape.com/documents/149d04516329df90404a5569/w/e5b5d2eb21cc5b28181d3510/e/8b731887c31f0a02032814c5
The author hasn't provided the model origin yet.