Features:Build-in microphone， support telephone call and musical listening.Super mini size and lightweight， diameter is about 22mm.Cosy earbud design， comfortable to wear.Bluetooth， wireless， 10m transmission distance， very convenient.Rechargeable， just need two hours to be charged， and enough to talk or listen music for 3 hours.Support connecting two devices simultaneously.Simple operation， one button with multifunctions.Supplied with earhook to make it hard to fall off.Specifications:Bluetooth version: Bluetooth V3.0+EDRStyle: In-earCommunication: WirelessTransmission distance: 10m / 32.8ftWireless frequency: 2.4-2.48gHZType of built-in battery: Rechargeable Li-ion batteryCharge time: 2 hours (3.7V)Standby time: up 12 hoursLasting talking time: up to 3 hoursEarphone diameter: 2.2cm / 0.9inPackage List:1 * Bluetooth earphone1 * USB cable1 * Ear hook