The latest RB-T39 handset is a lightweight headset with Bluetooth 5.0. It has a sensitive silicone microphone. The noise reduction will provide you with clear HD stereo sound quality. The handset is suitable for people who want to exercise, listen to music, drive a car, they are light and durable to use. Its ergonomic and lightweight design makes it fashionable and comfortable. Wireless version V5.0 Transmission distance <10M Transmission band 20-20kHz Impedance 16 Rated power 5mW Control unit 10mm Battery capacity 80mAh DC input 5V = 500mAh Play time 6H Standby time 200H