It is part of the F3SG series, which is Omron's current-generation safety light curtain family for guarding access to machinery, robots, and automated cells. The part ships in a Box package, which is the standard retail packaging for this sensor.
As a safety light curtain, the F3SG-4RR1840-25 is designed to detect personnel or objects entering a guarded area and signal the machine's safety controller to stop hazardous motion. The key selection parameters for this class are the protective field height, resolution (finger, hand, or body detection), and range — though the specific values for this variant are not detailed in the available record. The F3SG series is known for its slim housing and integrated muting and blanking functions, which reduce the need for external safety modules in many guarding applications.