*Improve the noise resistance by adopting dedicated IC(DC 3-wire) *Built-in protection circuit of reverse power polarity(DC 3-wire) *Built-in surge protection circuit *Built-in over current protection circuit(DC type). Except for PR08 type. *Long life cycle, high reliability with simple operation *Available to check the status of operation by Red LED indicator *Waterproof structure by IP 67 *Wide range of applications for replacement of micro switch, limit switch.