2.0 Stereo Channel Headphone In-line Microphone with Call Control and Tangle-free Cord Gold Plated 3.5mm Jack 4-pole TRRS Connector (Compatible with Smartphones, and Tablets) Extreme Comfort Leatherette Earcups. Acoustic Design: Dynamic, Closed-back Frequency Response: 20 - 20KHz. Driver: 50mm 32 ohms. Speaker Sensitivity: 113dB SPL (1mW) @1KHz Total Harmonic Distortion (THD): < 1% @1KHz / 0.775V. Maximum Input / Output Power: 200mW / 40mW Microphone Sensitivity: -58dB Cable Length: 62'