Powerful rechargeable lithium battery provides up to 13 hours of continuous talking/music time and 250 hours of standby with a single charge. If there is any issue with bluetooth customers need to ensure the headset has enough poweris turned on and has been successfully paired to the device.Then the Bluetooth function of the mobile is enabledAnd Bluetooth music device or the music devices with Bluetooth connector/Bluetooth stereo dongle must support A2DP.</br>Compared to all phones and PDA with Bluetooth V4.1 or Handsfree A2DP AVRCP Profiles features with faster & stable single transmissionclearer natural stereo sound quality with Lightweight designs. If the voice gets muffled Please  check that whether the range between the headset and the mobile is over 10 metersor there is wall or other disturbance or other electrical devices between headset and mobile.</br>Mic mute featurecompatible Voice DialingFlexible headbandtwo phones connected simultaneously. Support Bluetooth enabled PC messenger such as Skype??MSN Messenger or Yahoo! Messenger.</br>?Allows auto switching between music and calls. after you ended the call??the music will follow to be streamed in a few seconds. Short press Vol?? and ??Previous Track at the same time??will hear beep prompt to turn on/off Mic during talking sate.</br>?Every pieces test strictly??any feedback warmly welcomed??our after-sale service is for you to be completely satisfied.</br></br>Product Description</br></br><b>How to connect bluetooth with your smartphone:</b><br> 1: Ensure headset is in OFF <br> 2: When press and hold the MFB for about 7 seconds??until the indicator light alternates between blue and red??indicating that it is in pairing mode.<br> 3: Active the Bluetooth to search Bluetooth headset state. Normally??this is done by going to "onnect"or "Bluetooth" menu and then selecting the option to search Bluetooth devices.<br> 4: The phone will find BH-M20 and ask if buyer want to connect??press "es" or "Confirm" to confirm this action. <br> 5: Enter password or PIN "0000"??and press "es" or "Confirm" <br> 6: Pls note: This Process only needs to be completed One Time with each new device.<br> <b> Product Specifications:</b> <br> 1.Advanced 4 times Noise Cancellation technology?? With DSP digital signal processing function?? allow you to maintain a very clear and crystal conversation while talking. <br> 2.Balance & lightweight?? Headset?? Handsfree?? A2DP and AVRCP Profiles <br> 3.Frequency: 2.4GHZ - 2.4835GHz??ISM Band??Bluetooth range: 30 ft <br> 4.RF Sensitivity:75dBm <br> 5.Power supply: DC 5.0V /200Ma <br>