Drive:40 mmImpedance:32 OHMBluetooth version: Bluetooth v4.1 + EDRPower Level: CLASS IIOutput Power: 30mWBluetooth distance: 10 meters barrierFrequency response: 20-20000 HzOperating voltage range:3.0V-4.2VMicrophone sensitivity:-42dBwith A2DP / AVRCP high-quality stereo audio transmission and remote control protocolPowerful noise noise cancellation circuit(Active Noise Reduction)Wired and Bluetooth automatically switch to support audio inputCharging time is about1 hour (power indicator Charging: blue light lights, fully charged: blue light goes out)Dimensions: Diameter length 20MM. Width 15MM. 18mm highTalk time About 4 hoursMusic for about 3 hoursThe standby time is about 3-4 daysCharging Power: DC5V Power Interface [the hole] (computer USB port, mobile phone charger,car charger)Compatible: Compatible with Android, Apple,Microsoft, Symbian 99% of with Bluetooth cell phones(IOS cell phone has power display)