The IRB-RET retro-reflective photo eye is an external entrapment protection device type B1, non-contact sensor for use with automatic gates and doors. The light beam is near infrared and pulses at a rate of 300/second (300Hz). Since the reflector directs the beam back to the photo eye, wiring to the other side of the roadway is not required. The IRB-RET provides a signal to the gate or door operator that the beam is not obstructed. The operating range is up to 60ft.