A support arm for a vehicle mirror having at least one mirror head with a mirror pane which includes an upper holding arm made of plastic with an anchoring element for mounting on a vehicle, and a lower holding arm made of plastic with an anchoring element at the bottom for mounting on a vehicle. The amplification unit amplifies a voltage difference between a first input signal and a second input signal and outputs a first output signal and a second output signal. The tool holder and the grip housing can be moved relative to one another in a direction of rotation, and the switching motion thus comprises a rotary motion of the grip housing. A determination may be made that the scene has changed. The micro-processor then uses the status signals to synchronize the operation of each of the multi-way sensor switches to allowing the multi-way sensor switches to operate in a true three-way fashion.