Volkano Chromium Series Bluetooth Earphones - Black with Mic, SD Card Reader & Carry Case Bluetooth Version?4.2 chipset:JL Profile: a2dp,avctp,avdtp,avrcp,hfp,spp,smp,att,gap,gatt,rfcomm,sdp,l2cap Bluetooth Range? 10m Driver Size? 10mm Impedence: 32ohm Frequency Range: 20hz-20khz Sensitivity: 110dB at 1khz Battery: 90mAh Charging Time? 2hour Charging input: DC 5V Playtime(MAXIMUM volume ): 3-4hour Max Size for SD Card: 32GB What's in the box 1 x Volkano Chromium Earphones Black 1 x USB Cable 1 x Carry Case