1,blutooth earphone 2,Transmission distance:10M 3,On-line chat through Bluetooth wireless transmitter 6,Supports HSP and in-ear stereo earphoneFeatures:1,Transmission power:class2 / Frequency range:2.4GHz-2.48GHz 2,Transmission distance:10M 3,Operating voltage:3.6V / Operating current:≤35mA4,Charging time:2-3 hours, Talking time:up 6 hours, Standby time:100 hours5,Four-direction button for VOL+, ...