Technical Details Specifications of Headphones Driver: Neodymium magnets, 40mm, custom dynamic Form Factor: closed back, circumaural (over the ear) Response to Frequency: 10 Hz to 40,000 Hz Sensitivity at 1kHz: 100dBSPL/mW T.H.D: less than 2% Frame Material: Aluminum Memory foam and high-quality leatherette ear cushions A microphone Electret condenser microphone is the specification element. Response to Frequency: 50 Hz–18 kHz -42dBV sensitivity (0dB=1V/Pa,1kHz) Electret condenser microphone as a boom mic element Boom Mic Polar Pattern: Noise-canceling, bidirectional Boom Mic Response to Frequency: 50 Hz–18 kHz Sensitivity of Boom Mic: -42dBV (0dB=1V/Pa,1kHz) Integrated Mic Component: Condenser electric microphone Integrated Mic Omnidirectional Polar Pattern Integrated Mic Response to Frequency: 50 Hz–8 kHz Integrated Mic -33dBV is the sensitivity (0dB=1V/Pa,1kHz). Links and Characteristics Boom Mic Polar Pattern: Noise-canceling, bidirectional Audio controls: Bluetooth® volume and multifunction buttons, in-line volume and microphone mute Specifications of Batteries 20 hours is the maximum battery life. Time Spent Charging: