Shell for electrical device

A shell for holding an electrical device on an external supporter, the shell comprising:

• a plate;
• a sidewall extending from the plate, the plate and the sidewall cooperatively defining a receiving space for holding the electrical device;
• a plate-shaped rotation body being substantially aligned with and rotatably connected to the plate;
• and comprising an exposed surface and an inner surface at opposite sides thereof, the exposed surface facing away from the receiving space;
• and
• an adjustable rest located on the rotation body at the exposed surface of the rotation body, the rest comprising:
• two opposite connecting ends each rotatably connected to the rotation body;
• and
• a supporting end between the connecting ends and having a support point, the supporting end configured for standing on the external supporter at the support point and cooperating with the sidewall to hold the electrical device on the external supporter, the rest adjustable such that the supporting end is not located on a line coinciding with a center axis of the rotation body,
• wherein the rotation body is rotatable relative to the plate to adjust a distance between the support point of the supporting end and the sidewall.