B350-XT 203475 BlueParrott Noise Canceling Bluetooth Headset Parrott Button can be programmed with the Blue Parrott smartphone app. (iOS and Android). Unrivalled HD Voice call quality with 96% noise-canceling performance. Near Field Communication (NFC) for easy, instant pairing. Talk for 24 hours, and charge via micro USB. Use with two cell phones or a phone and PC at the same time. Durable all-day comfort. Microphone Frequency Response:100 Hz to 10 kHz. Sound Pressure Level is 123 dB plus or minus 3 dB at 1 milliWatt