ZCKD15 Sensors Limit Switch Head for use with XC Series. Telemecanique XCKM range of limit switches and accessories. These Telemecanique limit switches are the perfect solution for a multitude of applications including escalators, electrical assembly equipment and material handling. A limit switch is commonly made up of an actuator head, switch body and receptacle, predominantly used as part of a control system within industrial applications such as those listed before.