Logitech EasyFit™ Earbud Premium headset f/ mobile phones. Headphone frequency: 100 - 5.000 Hz, Impedance: 150 Ом. Microphone frequency: 100 - 10000 Hz. Compatible products: Works with virtually any mobile phone. Signal-to-Noise Ratio (SNR): 55 dB, Minimum system requirements: Requires Logitech EasyFit Connector (sold separately), Compatibility: Telephone