Specification:<br />* Main features: call handsfree・ listen to the music・voice prompts<br />* After power on・ press the power button twice・ English and Korean switch<br />* Press + or - to change the song・Long press the + or - to adjust the headset volume<br />* Bluetooth version: 4.0<br />* Operating Frequency: 2・400 ~ 2・4835 GHz<br />* Receiving sensitivity: <-83 dBm<br />* Transmitting power: automatically detect dynamic transmit power・ maximum 4dBm<br />* Support A2DP function (stereo music function)<br />* Supports AVRCP function (Audio / Video Remote Control)<br />* Supports HFP function (speakerphone)<br />* HSP support functions (Headset Profile)<br />* Communication: Double C<br />* Channel bandwidth: 1M<br />* Accessible interior distance calls:> 8m<br />* Accessible outdoor distance calls:> 10m<br />* Frequency response: 20Hz ~ 20KHz<br />* Battery: 3.7V・ 220mA lithium battery<br />* Machine operating current: <30mA<br />* Machine Shutdown Standby current: <1.5uA<br />* Machine Power Standby current: <15mA<br />* Speakers: 20mW * 2<br />* Work time:   4h<br />* Standby time:  15 hours<br />* Charging current: 100 +/- 15mA<br />* Standby life:  2 months<br />* Battery Standby time:  240 hours<br />* Charging mode: USB Charging<br />* Charging time: about 2 hours<br />* Echo: in a non-closed environment・ echo-free<br />* When it's not paired with Bluetooth device・ headset will automatically shutdown after 5min.<br />* When there is an i