The TXF-125E is a battery operated quad photoelectric beam sensor designed for compatibility with leading wireless systems; reducing the time and cost of permanent installations and allowing the use of Active Infrared Beams on rapid deployment or temporary installations. With 4 selectable frequencies, multiple beam sets can be used in both linear and stacked configurations without risk of crosstalk, further assisted by a transmitter power function that allows the user to set 25/50/75/100m zones.