Ultra JZ-1088F2 Rechargeable Portable Sound Amplifier Hearing Aid

JZ-1088F2 Rechargeable Ear hearing aid mini hearing device ear amplifier digital hearing aids for the deaf and elderly. 

• Frequency range:100-4000 Hz
• Battery :1.2V
• Signal to Noise Ration:≤28db 
• Gain:30db 
• Distortion:≤6% 
• Working Current:≤3MA 
• Gain: 30db
• Working Current: Less Than 3mA
• Distortion: Less Than 6%
• Charging time: approx. 3 hours
• Working time: 8-10 hours
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• Adjust volume to the minimum before wearing.
• Choose an earplug of slightly bigger size to avoid whistler.
• Increase volume gradually to avoid sudden increase in sound.
• If you hear a howling, check the ear (silica gel) is appropriate and whether the size of plug is tight, the appropriate choice of earplugs and plugged, make sure no air leakage.
• Keep the ear plug clean
• Remove the battery if you don't use it for long time.