Operation voltagev30v 42v modelbh320 input voltage v37v cable lengthcm0 materialplastic typeearhook general usemobile phone cellphone functionsports volume control with microphone noise cancelling communicationwireless bluetooth connectorsusb memory capacitynone speaker diameter12mm speaker sensitivitydb953db speaker frequency response20hz 20khz microphone unit4mmx15mm microphone spl323db10w01m microphone impedancekohm2000 microphone freq