Safety rope switches immediately switch off the machine drive if the rope is pulled or there is a tear in the rope. This condition remains locked till the reset pushbutton is pressed when the rope is under correct tension. Different variants are available for different rope lengths. An additional emergency stop key can be mounted on both sides of the switches. With the ZANDER assembly / rope tensioning system ZTK, the pre-tension of the rope can be easily set so that green arrows are visible in the display window of the safety rope switch. This simplifies the assembly, troubleshooting and maintenance procedures.