Best Bluetooth 5.0 Invisible Rechargeable Hearing Aid Digital Audifonos Ear Sound Amplifier Enhancer Call Music rustling of leaves,the sound of birds 10db(normal) running water sound 10-20db(normal) whlsper 15-25db watch walking sound 30-40db mile hearing lo daily taling sound 40-60dbmoderate hearing lo dog barking 60-80dbmoderate to severe hearig lo speak loudly 80-100dbmoderate to severe hearing lo phone ringtone 80-90dbextrmely severe) firecrackers sound 100-120dbextrmely severe) Suitable for mild to moderate hearing lo 100db (Reference hearing your audiogram)as show If you do not have audiogramplease refer to the below table Charger INPUT: AC100-240V, 50-60Hz / 0.15A ChargerOUTPUT: 5V, 1000mA Instructions: 1.)Thewireplugconnectedtotheheadset.Thenearplugconnector(hard)totheheadset, earbuds(silicagel)toconnecttotheheadphoneconnectorpedestal 2.)Thebatteryinstallation:Gentlyopenthebatterycompartmentcover,putabattery intothebatterycompartmentintherightdirection,thenclosethebatterycompartment. 3.)Beforeyouusethisitem,youhavetoturntheON OFFswitchtoOff,andturnthesound volumetominimum. 4.)Thenputthisitemonyouear,keepittightly 5.)Next,turnthisitemON,adjustthevolumeuntilyouhearclearsound Company information In 2019, it invested and set up a factory in Xiamen to build a large domestic hearing aid production and r&d base with an area of about 12,000 square meters. Since the introduction of automatic production system in 2018, the company has taken the lead in realizing automatic production of hearing AIDS in China. Accurate automatic operation has greatly improved production capacity and made quality more stable