A kind of external adjusting device includes that at least one is configured to the permanent magnet for rotating about the axis, linearly extension and second handle are located at the second end of device to first handle at the first end of described device, and the second handle extends along the direction for the axis for substantially deviateing the first handle. The external adjusting device further comprises the motor being mounted on inside first handle, it further include the first button of one of the neighbouring first handle or second handle positioning, first button is configured to be clamped the thumb manipulation of the hand of one of the first handle or second handle. First button is configured to driven motor so that at least one permanent magnet is rotated along first direction around the axis.
