Wireless Type: Bluetooth V2.1+EDR Class 2 Power Supply: Rechargeable 400mAH; Li-Polymer Battery Operating Time: Up to 20 hours (Playback Time) Distance: 30M Headphone Frequency Response: 18Hz-22KHz Headphone Signal to Noise Ratio(SNR): 95 dB Weight: 71 g Features: Color: Gray Standby Time: Up to 400 hours Total Harmonic Distortion: 0.1% Enjoy your music and answer phone calls with just one click. The P311 Bluetooth headset is ideal for people on-the-go. Connect it with the UD1 or the UD2 to make it compatible with your notebook and PC as well!