Wireless Hearing Aid Sound Amplifier InEar Hearing Aid Hearing Amplifier for Elderly Condition: Item Type: Hearing Aid Material: ABS+ Silicone Power Supply: 1pc A10 button battery (not included) Maximum Saturation Sound Pressure Level (OSPL90) : ≤128dB±3dB Full Gain: 25±5dB Total Harmonic Distortion (THD): F> 1000H≤15％ F <1000H≤10 Frequency Response: 450-3800 Hz Equivalent Input Noise: ≤32dB How e: 1. Choose the right size earplugs to avoid squeaking, and use the complimentary tools to adjust the volume 2. First, the volume should be adjusted to the minimum to avoid the noise generated when the battery is loaded 3. Load battery, pay attention to the direction of the battery positive and negative 4. Adjust the appropriate volume and put on the hearing aid, pull the traction line can remove the hearing aid Not suitable people: (1) Not applicable to hearing loss between 0 and 30dB. (2) Sudden hearing loss, especially within three months. (3) Tinnitus symptoms (4) Hearing loss is very fast in a short time (5) Hearing asymmetry, the reason is unknown (6) Severe otitis exteriority, suppurative otitis media Note:1. Suffering from otitis media patients must be banned. 2. Do not put the hearing aid in high or low temperature environment. 3. Please do not use different types of batteries. Please replace the batteries after the batteries are used up. 4. Please do not use the hearing aid for a long time, high volume is bad for your ears, if you feel uncomfortable, please stop using. 5. When not in use for a long time, please take out the battery, in order to prevent battery leakage corrosion hearing aid. 6. Do not clean the hearing aid with water or organic detergent.Don't put it in the water. 7. Don't throw a wasted hearing aid into a fire. 8. Please regularly do maintenance work on the hearing to ensure that the hearing aid clean, an object blocking the sound hole will affect the use effect.