1 pair (2 packs) of hearing aid amplifiers noise eliminating battery-operated suitable for adults and seniors fendidi notice:: 1. why is there noise or a whistle, how to solve it?<br> please check that the size of the earplug ,<br>make sure it is tightly put in ear canal.<br> otherwise it will cause noise and howl, <br>that is not the quality problem. 2 packs battery-operated hearing aid personal high quality sound amplifiers ,<br> noise eliminating,suitable for adults and seniors<br> specification for cic amplifier : peak ospl 90 ( db spl): 129db<br> haf ospl 90 ( db spl): 120db<br> peak gain(db) : 50db<br> haf/fog gain (db) : 40db<br> cic hearing aid parameters<br> material:resin<br> size: 0.52*0.68 inch<br> weight:2 gram<br> battery life:150 hours<br> eath one can fit for right ear and left ear<br> 1.personal hearing amplifier equipment is comfortable to wear,<br> silicone material, soft to the touch, comfortable to wear in both ears.<br> 2.the hearing amplifier has a built-in dual noise reduction function to reduce external noise.<br> 3.the hearing amplifier is easy to operate and equipped with a switch key,<br> a volume gear button, and a mode button.<br> 4.those hearing amplifier has four different modes; <br>high, low, medium, and wide to meet different occasions. package including:<br> 2 x hearing aids<br> 10 x large,mid,small size ear plug<br> 2 x cleaning brush tool<br> 6 x battery: model:a10 for hearing aid<br> 1 x easy read user manual<br> please buy a10 battery if you need extra battery