1. Model: V21 2. Transmission range: 10 meters 3. Function: power display, voice control, call function, support music, NFC function, multi-point connection 4. Bluetooth protocol: p5.0 5. Channel: Stereo 6. How to use: earbud 7. Whether single or both ears: unilateral hands free 8. Single ear package size: 13x7x2.8cm 9. Single ear set weight: 27g
