Bluetooth headset Get your voice across clearly Wireless bluetooth headset adopts HD dual microphone and CVC 8.0 noise reduction technology, which makes the sound clearer and the connection more stable. When you are talking to someone in a noisy environment,The dual mic noise cancelling technology will filter out background noise, so that the other party can hear you clearly. It comes with a large capacity of 450 mAh charging and storage case, so you can fully charge your earphones approximately 5 times. You can easily carry it around without worrying about running out of battery for commuting to work or business trips. Ergonomics and comfortable design, Tailor-made design Ultimate comfort ear gels are available in 3 different sizes (S,M,L) to provide a snug.It fits all types of ears comfortably.Even if you wear it all day, there will be no discomfort and fatigue. Rotatable&Stretchable design make it friendly to fit a wide range of right/left ear shapes. Lengthen the ear hook, to fit big ears; Retract the ear hook, to fit small ears and can be ensure a firm fit. It is also suitable for someone who wear glasses. NOTE: * Please turn the volume of your mobile phone to maximum first to prevent the sound of the bluetooth headset being too low. * Please make sure to remove the insulating film inside the charging case. Otherwise you will not be able to charge the bluetooth headset Please note that this is a product specification and not a defect. New 5.1 Bluetooth chip The bluetooth earphone uses Bluetooth 5.1 chip, provides instant pairing and uninterrupted stable transmission.can transmit sound quickly and reduce the call delay, and can transmit sound clearly to the other party's ear. One Step Auto Pairing Pick up the wireless headset from charging case, they will power on and pair with each other automatically. Then active your bluetooth pc to search “YYK-520” to connect. After the first successful connection, the single ear bluetooth cell phone headsets will automatically connect to the last paired device when reboot. single ear bluetooth for work, home and office.s. SWEATPROOF AND DUSTPROOF Bluetooth headset 5.1 is sweatproof and dustproof. Whether in the gym, outdoor sports are unlimited, and music is endless. Don't worry about sweating a lot. Music with me "moving", IPX8 sweatproof and dustproof. Fast type-c charging port With fast charging function, the earphones are fully charged in only 1 to 1.5 hours, and the charging box is fully charged in only 2 hours，and the charging case can charge the Earpiece Bluetooth wireless for 5 times, which means you can use it for up to 35 hours in total, and the standby time is long to 180 hours. Product Advantages Small and PortableEasy to wear with one handOne-click answer/hang upLong standby timeSimple and easy to useNoise cancelling bluetooth earpiece with clear sound Specification / Packing Contents Wireless Version: V5.1+EDRSupport AVRCP V1.6.A2DPV1.3.HFP V1.7 Simultaneous LE and BR/EDROperating Range: up to 33 feet (accessibility, empty place)Playing Time:About 5 hoursStandby Time: 8 daysCharging Time: About 1.5 hoursPacking Contents: Headset * 1/ Earbuds Cap*2/ Charging Case *1/USB C Charging Cable *1 / User Manual * 1 Operating Instructions Call Siri Long press on the on button fou 1s Close Siri Click the on key Next / Previous Song Press the volume +/- button for 1 second Volume +/- Click the Volume +/- button (Note: When the headset volume is increased to the volume limit via the headset volume + button. Please try to increase the volume through the phone.) Answer / Hang up Click the on key Refuse to answer/Cancel call Double click the switch/Click the on key (Used during call) Mute on/off Press MFB button for 2 seconds Third party call handover Click the MFB key Reset Make sure the headset is turned off and press the Switch button for 8 seconds. And then, put the headset into the charging case