Features:Please read this user manual carefully and keep for future reference.Important Safety InformationDON’T use the headset at a high volume for any extended period. To avoid hearing damage， make sure to use your headset at a comfortable， moderate volume level.DON’T use the headset during any activity requiring your full attention， e.g.， while driving， riding a bike or crossing streets.Keep the headset， accessories and packaging parts out of reach of children to prevent accidents and choking hazards.Always keep the headset dry and DON’T expose it to extreme temperatures (hairdryer， heater， extended exposure to sunlight， etc.) to avoid corrosion or deformation.DON’T use the headset if you feel obvious discomfort， irritation or other adverse reactions.Package ListBluedio Ci3 Bluetooth headset USB charging cableEartips (S，M，L) Bluedio CI3 Bluetooth V4.1 sports earphone with mic for tablet PC smartphoneStandard Bluetooth 4.1Near zero distortionLow power consumptionStreamline designSweat-proof design with high qualityCompact and lightweight， providing comfortable wearing experienceEasy to operateDouble earplugs designLight weight and portable， easy and convenient to carryIn ear style， very convenient when driving or doing sportsComes with S / M / L different sizes of earbuds for more comfortable wear