Product detailsNON EAR PLUG DESIGN - 2019 upgraded headphone version is the Ear-hook design, not in-ear, free from eardrum damage. Only weight for 8g and easy to carry, suit for all peoples, do not fall when running. withglasses is ok. With Built-in microphone is for Hands-free calling.FAST CHARGING - Built-in high performance lithium battery, 10 hours continuous answer phone, 3-5 hours music playing time, 20 days standby time, 1.5 hours quick charge.SPEAKER UNIT IS EXTERNAL - Loudspeaker close to the ear but it is not inside the ear, will not plug block the ear canal. Listening to the surrounding environment during a call or music, Safer on the road or in some scenes and more portablefor business, work.How to pair two earphones together and hear music simultaneously in both ears?1.Just hold the button of two earphones for about 5 seconds untill the LED keep flashing in red and blue,you will hear a prompt.2.Double tap the button of either earphone,two earphones will then automatically pair to each other with saying \'Pairing Success\'.3.Open your cellphone\'s bluetooth,searchHQB-Q25from the list,after successfully connected and paired,you will hear a \'paired\' voice notification.(It will gose to standby then sleeping mode if cancel pairing)How to switch language?1.Just hold the button of two earphones for about 5 seconds untill the LED keep flashing in red and blue.2.Triple tap or keep holding the the button for 2 seconds,you will hear a \'English\' or Chinese prompt.Special Feature:1.Advanced Bluetooth 5.0 Chip.Compatible with all the Bluetooth enabled devices. iPhone,Android cell phones,tablet,PC,TV etc.2.Can be used with single or dual-paired mode, you can enjoy HiFi stereo alone by single or dual-paired headphones.3.It supports incoming number calling,iOS and Android phone battery display.Product description:Bluetooth version : V5.0 + EDRWireless protocol: A2DP1.3/HFP1.6/HSP1.2/ AVRCP1.6/D11.3Transmission frequency : 2.4GHz (2.402-2.480GHz)Transmission distance: 10mSpeaker sensitivity: 953dBFrequency response : 50-10kHzMicrophone sensitivity : 50-18kHzStandby time : about 120 hoursPlay time:4-5 hoursCharging time : about 1-2 hoursNet weight: 0.28 oz/piece