High Quality Tinniy Product Voice Enhacner Hearing Aid Louldy Amplifier Sound Analog Mini Portable S-212 Note: 1.For Australian users, your hearing aid will not be equipped with batteries due to your national policy 2.This headphone for deaf suit for mild to severe hearing lo person, it is popular in hearing aid medical supplies market because of it's smaller size and nice looking with best sound, clearly voice. Products Informations: 1. Simulation program chip standard ear canal hearing aids. 2. New type D chip amplifier. 3. Low-power circuit design. 4 mini volume adjustment function. 5.10A battery design. Products technical parameter 1.Max Out: 120dB 2.Max Gain:30dB 3.Average Gain:38dB 4.Harmonic Distortion:a)10%(Frequency< 1000Hz) b)4%(Frequency >1000Hz) 5.Equvi Input Noise:30dB 6.Frequency Range:250Hz~3500Hz Package Including 1* Deaf-aid earphone 1* hearing aid battery A312 3* silicone different size ear plugs (small, medium, big) 1* cleaning wax brush 1* white gift box 1* English manual 1* FEIE warranty card Note: 1) It is super mini size and light weight, not easily to be seen; 2) Adjust the volume to the minimum before wearing; 3) Increase the volume gradually to avoid sudden increase in suond; 4)When you not use, take battery out of saving power; 5) Convenient for watching moive, enjoy the drama, attending meeting, watching TV or haveing cla; It can help you hear the sound clearly and loudly ! Problem if you met: Pls read the manual at first if don't know how to use it or contact our customer service. If you feel the whistling sound: 1. Choose a suitable ear plug to make the product sealed in the ear canal 2. Low down the sound volume 3. When you put into battery , please be quick , to put the product into the ear Note: 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. Keep the ear plug clean Remove the battery if you don't use it for long time.