["Description:\r\nbrand new and high quality\r\nPocket Hearing aid\r\nMax Sound Output: 129±5 dB\r\nMax Sound Gain: 55dB ± 5dB\r\nHarmonic Wave Distortion: ≤5%\r\nFrequency Range: 450~3500 hz\r\nInput Noise: ≤30 dB\r\nBattery: 1 x AA battery (included) \r\nWorking Voltage: dc1.5V \r\nWorking Current: ≤4mA \r\nColor: As the picture shows\r\nItem Size: 6.6 x 4.3 x 1.6cm\t\t\t\t\t\t\t\t\t\t\t\t\t\t\r\nPackage Size: 8.5 x 12 x 3.3cm\t\t\t\t\t\t\t\t\t\t\t\t\t\r\nNet Weight: 29g\r\nTransition: 1cm=10mm=0.39inch\r\nPlease allow 1-3mm error due to manual measurement. pls make sure you do not mind before you bid.\r\nDue to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!\r\n\r\nPackage included:\r\n\r\n1 x F-16 Hearing aid \r\n4 x Earplug (different sizes)\r\n1 x AA battery\r\n1 x User manual\r\n1 x Box\r\n\r\nNote:\r\n\r\nAdjust volume to the minimum before wearing.\r\nChoose an earplug of slightly bigger size to avoid whistler.\r\nIncrease volume gradually to avoid sudden increase in sound.\r\nIf 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. \r\nKeep the ear plug clean\r\nRemove the battery if you don'for t use it for long for time."]