Bluetooth Specification: Version 1.1 Frequency Range: 2.4Ghz Spectrum talk time: 5 hours stand-by time: more than 120 hours Working Distance Range: 10M Charging Time: 2 hours Input: 100-240Vac 50Hz 0,1A Output: 5.7Vdc 250mA Lightweight: Only 9g Dimensions: 71(L)x25(W)x24(T)mm 1.Multifunction buttons S1 button: for Power On/Off, Answer/End calls, Volume-up 2.Microphone Uni-directional, high sensitive microphone reduces background noice and gives high clarity of sound 3.Comfortabe detachable earplug fits perfectly and securely over either ear and gives ultra high quality sound.