... ) 280 metersRF Frequency868MHz/433MHz/315MHzCrosstalk rate1/4,200,000,000Sound Level(typical)85dBA @3 ft(1m)Power consumptionStandby mode:<200mW<10mWWorking ... power required.16 polyphony ring tones, built-in amplifier, good sound quality makes it pleasant to hear.Self-learning code system ...