Contactless RFID safety switches. Plastic case switch and transponder for use on machines with low inertia. Specifically designed for industrial machines fitted with doors, covers or guards with imprecise guiding. They are ideally suited for machines subjected to frequent washing or liquid spray, and exposed to shocks and vibrations. Contactless system composed of a microprocessor-controlled switch and a transponder. The reader and the transponder are factory-paired so as to load into the transponder a unique code shared with the reader. This saved digital code is the unique “key” accepted by the paired reader. This type of switch is thus difficult to tamper with. As long as the transponder is in the reader detection zone (<15 mm), the machine will run normally. When the transponder goes outside the field generated by the reader, the reader stops the machine, indicating that the safety guard is open.