a base seat;

an axle unit including an upper axle that extends into the base seat; and

a restoring unit permitting the upper axle to extend therein, the restoring unit being for restoring the upper axle to its original position after the upper axle is rotated;

wherein the rotation device further comprises a buffer unit that permits the upper axle to extend therein and that is disposed in the base seat, the buffer unit being for damping the rotation of the upper axle when the upper axle rotates back to its original position; and

wherein the base seat includes a casing that accommodates the buffer unit, the casing having an inner surface, the buffer unit including a buffer rotating bracket that is co-rotatably connected to and penetrated by the upper axle, a buffer moving bracket that is movably mounted to the buffer rotating bracket, a buffer abutment wheel that is mounted to the buffer moving bracket and that abuts against the inner surface of the casing, and at least one cushion member that is mounted to the buffer rotating bracket and that abut against the buffer moving bracket, the buffer abutment wheel moving along the inner surface of the casing when the upper axle is rotated by an external force, the cushion member being for damping the rotation of the upper axle when the upper axle rotates back to its original position.