AUX, 40mm is the speaker's diameter. 32 ohms of impedance Sensitivity: 1kHz, 102dB+/-3Db Response to frequency: 20 Hz to 20,000 Hz Maximum power input: 120 mW Type of plug: AUXCable; length: approximately 2.1m/6.9ft; weight of headphones: approximately 241g/8.5oz Included in the package is one headphone.