Importer520 Handsfree Stereo Earphones Earbuds with Microphone For Nokia Lumia 920 (AT&T)- New Black Completely eliminates unnecessary tangles from the equation Crystal clear and high quality voice for both talking party, noise cancellation, high-velocity element for excellent stereo effect. The handsfree use soft and environmental protection wire instead of the common wire, and the soft silicone rubber in-ear cushion of handsfree is comfort and using convenience. Frequency Range: 20Hz~20kHz Sound Pressure Level: 107dB3dB/100mW Total Harmonic Distortion: &lt;=5,(Input Power: 10mW; Frequency Range: 20Hz~20kHz) Accessory Only