The BEAMLRK allows reflected beam detectors to be installed at separations
between 230 and 328 feet (70 to 100 meters). At these distances, four 8" × 8"
reflectors must be used to provide enough reflected infrared light. This kit
includes 3 additional reflectors with new test scale legends. The reflector
included with the transmitter/ receiver unit is the fourth reflector to be used.