This tag has an U1 chip using Ultra Wide Band (UWB) which means that iPhones 11 and above also equipped with those chips will be able to locate those tags from 80m away with a +/-30cm accuracy. U1 UWB uses short pulses at 6.24GHz and 8.2GHz and positioning is done by combining time of flight (ToF) and angle of arrival (AoA).