About this automatic switch we operate 2 phones to a phone jack Fritzbox. The product is working properly. However, this device is intended to be installed on the wall and therefore does not have a connecting cable. For easy connection without installing this equipment there for an extra charge of about 8, - Euro, with connecting cable - simply insert> unit beside the Fritz box, plug in the cable and you're done. For the proper function, there are 5 star.