Feature:Constructed with aluminum alloy casing， high quality and durable.Fashion and laconic cylinder shape design， full of modern feel.Support bluetooth calls handsfree.Bluetooth Music/TF Card Music/Exterior Music Aux-in Supported.Stereo and Bass Sound EffectSpecification:Casing Material: Aluminum AlloyFrequency Response: 150Hz-20KHzOutput Power: 3W*2Bluetooth Standard: RDA 3.0Frequency: 2.402-2.480GHzMIC Sensitivity: -38dbSpeaker Sensitivity: better than -82dBmRange: 10-30 metersWorking Voltage: DC3.7-4.2VWorking Current: 150mAPower: Built-in 3.7V，400mAh Li-ion Battery.Charging Voltage: DC4.8-5.5V， 200mA.Music Playing Time: more than 2.5 hours.Handsfree Talking Time: more than 4.5 hours.Standby Time: more than 20 hoursDimensions: 71.2(Diameter)x42.5(H)mmUnit Weight: 170gSize: 72x72x43mmBroadcast time: 2 hoursConnection: USB Bluetooth connection card readerColor : silver ， black ， gold， rose goldPackage included: 1 x Bluetooth speaker