... 6 hours,Headphone playback songs in 60 hours or more MP3,WMA,WMV,ASF Headset maximum output:(L)10mW+(R)10mW ... Frequency response:20Hz---20KHzSNR(Signal Noise Ratio): 85DbSNR: 45dBMP1,MP2,MP3,WMA,WMV,ASF,WAV Operating temperature -5 To 40 degrees ... output power Continuous output power to more than 2W voice Alarm whistle function According to the guests, music whistle can be ...