Elderly BehindtheEar Hearing Aid Noise Reduction Portable Hearing Amplifier Hearing Aids Set Condition: Item Type: Hearing Aids Material: ABS Power Supply: 1 x A312 batteries (not included) Function: Compensation for hearing loss. Scope of application: It is applicable to hearing impairment caused by conduction, sensory nerve and mixed hearing loss due to aging, tympanitis and various diseases caused by drugs Button to adjust the listening mode: The default listening program on startup is Listening program 1. Click the listening program every time Select the key and listen the following sequence: Listen procedure 1- Listen procedure 2-listen procedure 3-Listen procedure 1 Listening procedure 1(medium-to-high frequency) is used by people with medium-to-high frequency hearing loss, such as age-related hearing loss, perforation of eardrum, etc. Listening procedure 2(high frequency) for use by patients with high frequency hearing loss, such as medically, congenital or neurologic hearing loss; Listening procedure 3(full frequency) 1 is full frequency amplification, suitable for hearing loss caused by otitis media, strong vibration, perforation of eardrum, etc. Usage:  1. Replace the earplug parts.Select the appropriate size and place it in the earplug connector 2. Disassembly.Hold the earplug in your hand and separate the tube from the earplug. Precautions:  1. Avoid being swallowed by children.Please keep hearing aids and hearing aid batteries away from children 2. Do not charge the battery or put the dead battery into the fire to avoid explosion 3. Do not put the battery together with food and medicine 4. Do not put the battery in the mouth.If you swallow the battery, seek doctor's attention immediately.Swallowing hearing aid batteries can be life-threatening 5. Hearing AIDS should be used for people with hearing impairment, can not be used on anyone else Special users: (1) Children should not wear hearing aids under the guidance of adults (2) A mentally ill person should consult a physician or a professional audiologist before wearing a hearing aid 6. Regular checkups: Contact your hearing aid specialist regularly and he or she suggests a schedule for changing accessories or checking equipment 7. Pay attention to avoid moisture 8. Waterproof: Do not wear it when swimming. If the hearing aid falls off accidentally and is put into the water, do not use the dryer to dry it.You can dry them with a soft clean cotton cloth and place them in a ventilated area.