Bluetooth Headset Wireless 4.1 Stereo Music $ 4.84 Product Information: Product parameter 1) Driver: 15mm 2) Impedance: 32 OHM 3) Bluetooth version: Bluetooth v4.1 EDR 4) Bluetooth use frequency band: 2.4GHz 5) Power level: CLASS II 6) Output power: 30mW 7) Bluetooth distance: 10 meters without barriers 8) Frequency response: 20-20000Hz 9) Operating voltage range: 3.0V-4.2V 10) Microphone sensitivity: -42dB 11) With A2DP/AVRCP high-quality stereo audio transmission and remote control protocol 12) Powerful noise cancellation circuit (active noise reduction)