The present document specifies technical characteristics and methods of measurements for avalanche beacon transmitter-receiver systems operating from 456,9 kHz to 457,1 kHz. The frequency range 456,9 kHz to 457,1 kHz is EU wide harmonised for emergency detections of buried victims and valuable items devices according to Commission Implementing decision (EU) 2019/1345 [i.9]. An avalanche beacon comprises in one unit at least a transmitter/receiver including antenna and battery.