DANYIN BH69 Unilateral Bluetooth Business Talk Headset Customer Service Wireless Voice Wheat Microphone: 1. Directionality: one-way 2. Sensitivity: -44dB 3. Impedance: within 2.2 kΩ 4. Microphone size: about 6.5 x 5.0mm 5. Straw length: about 23cm Trumpet: 1. Impedance: 32 ohms 2. Frequency response: 20Hz-20kHz 3. Output sound pressure: within 96dB 4. Plug type: USB + four-level single plug 3.5mm 5. Bluetooth version: 5.0 6. Bluetooth distance: within about 10 meters 7. Battery capacity: 160mAh 8. Charging port: Micro USB 9. Charging time: about 1.5h 10. Playing time: about 8h 11. Diameter: about 30mm 12. Weight: about 117g Features: 1. Adopt V5.0+BR+EDR+BLE Bluetooth technology version, fast transmission 2. Composite biological diaphragm, wide sound range 3. Built-in ceramic antenna, stable signal and high adaptability 4. One-point microphone, reduce background noise and pick up sound more clearly 5. 30mm neodymium boron magnet speaker, loud sound 6. The unilateral body can be adjusted, and the steel bow beam on the left can be stretched about 1-2cm 7. The rotatable angle of the straw is about 120 degrees, and the metal gooseneck has good fixation