An exemplary electrical device includes a first main body; a second main body; and a rotatable mechanism pivotally connected the first main body and the second main body. The rotatable mechanism includes a first rotation unit and a second rotation unit. The first rotation unit is capable of making the first main body rotate around a second rotation axis in a plane perpendicular to the second rotation axis. The second rotation unit is capable of making the first main body rotate relative to the second main body around a first rotation axis.