Operation voltagev30v 42v modelm9 input voltage v37 cable lengthcm60cm power supply37v materialrubber plastic metal typein ear general usesports fitness functionbluetooth noise cancelling sports volume control with microphone communicationwireless bluetooth connectorsusb memory capacitynone speaker diameter12mm speaker sensitivitydb1033db speaker frequency response20hz 20khz microphone unit4mmx15mm microphone spl383db10w01m microphone imped