Full metal hand microphone with superior sound quality Carrier Frequency Range : 514-542MHz RF Power Output : LOW (5dBm -3.16mW) - HI (10dBm-10mW) Oscillation Mode : PLL synthesized Frequency Stability : +/-0.002% Frequency Response : 40Hz – 17kHz Microphone Capsule : Dynamic Battery : 3V DC (2 x 1.5V AA series batteries – Batteries NOT included!) Expected lifespan for 2500mA AA-size batteries: RF transmit power = LOW: +/-20 hours RF transmit power = HI: +/-12 hours