Smart Bone Conduction Wireless Bluetooth Stereo Ear Headset Outdoor Sports Music Earphone Specifications: Basic Spec Blue tooth IC CSR8635 Speaker Type Bone conduction technology speaker, 1w dual speaker Battery 230mAh Polymer battery Mic Anti\u2010interference microphones, \u201050DB Play time 5h Standby time 10days Effective range 10m Mono\/Stereo Stereo Blue tooth version 4.0 Weight 57g Bluetooth Class(1\/II) II BQB included(Y\/N): No Bluetooth Profile a2dp\/HFP, HSP, AVRCP, GAVDP, AVDTP Receiving Sensitivity 88dBm Impedance 32Ω Frequency range 20\u201020KHz FM No Charging MICUSB port and need 2h TF card No System language No Indicator light Status Red light flashing rapidly: Lack of Power; Red Light on: Charging; Blue Light on: Full charged; Blue and red lights flashing: Matching; Blue light double flash slowly: fail to match, maybe the device is power off, or the distance of both is over 15m; Blue light flash slowly: Matched\/dialing\/playing audio; Blue light flashing rapidly: Call coming. Basic Operation Operation Headphone control Prompt tone Answer call Click the Multifunction key Buzzing once Ending call Click the Multifunction key Buzzing once Reject call Long press Multifunction key for 1s Buzzing once Switch song Long press “+”“-” button No Volume control Click the volume button “+”“\u2010” Buzzing once Play\/Pause phone music Click Multifunction key No Power on Long press Power button 3seconds Prompt tone\/buzzing Power off Long press power button 3seconds Prompt tone\/buzzing BT disconnecting Prompt tone\/buzzing BT connnected Prompt tone\/buzzing Match again\/manual matching Shutdown state long press power button 6seconds Buzzing twice and prompt tone Low power Prompt tone\/buzzing Up\/down Click “+” “-“ button No Matching Method 1. Shutdown state long press power button 6seconds; 2. Search bluetooth device on your phone or other digit