Specs for bone conduction earphone:
Bluetooth chip: CSR8635
Bluetooth version: 5.0
Effective range: 10M
Frequency range (Hz)﹕20HZ--20KHZ
Impedance (ohm)﹕8Ω
Receiving sensitivity (dB)﹕88dBm
Battery: 200mAh Power battery
Talking time(H)﹕6H
Music time(H)﹕6H
Standby time(H)﹕10 days
Charging time(H)﹕2H
USB port: MIC USB
Product size﹕139*104*60mm
Product weight﹕36g

Specs for hearing aid transmitter(sound amplifier)
Bluetooth version: 5.0
Emission sensitivity: 2dB
Charging voltage: DC5V
Transmission distance: ≥ 10m
SNR: 95dB
Mic sensitivity: - 40 ± 3dB omnidirectional
Talk time: 8-10 hours
Music time: 8-10 hours
Shutdown standby time: 80 days
Charging time: 2-3 hours
Battery capacity: 400mah
Working current: ≤ 40mA
Shutdown current: 1.4UA