Features: brand new and high quality hearing aid sound amplifier. super mini size and light weight, not easily to be seen. adjust volume to the minimum before wearing. increase volume gradually to avoid sudden increase in sound. convenient for watching movie, enjoying the drama, attending meeting, or having class, it could help you hear the sound clearly and loudly. Specification: 1. max sound output: 1105db 2. sound gain: 30db 3. total harmonic wave distortion: 10% 4. frequency range: 300-4000hz 5. input noise: 40db 6. voltage: dc1.5v 7. current: 4ma 8. color: as pictures Note: 1. patients with otitis media or ear abscess are forbidden to use. 2. do not use it at high volume for a long time, otherwise it will hurt your ears. if you feel uncomfortable, please stop using it. 3. always maintain the product to prevent the earplugs and collection holes from being blocked by foreign objects, which will affect the sound amplifier. 4. avoid product vibration and drop. do not store or use in a humid or hot environment. 5. do not throw away the scrapped battery as ordinary garbage, it should be treated with special equipment. 6. if not used for a long time, remove the battery. otherwise, the component will rot over time, producing a battery that rots. 7. do not use this product in potentially explosive or hazardous environments. 8. keep the machine away from children (the product is small in size and avoids children swallowing) Package Include: 1 x Hearing Aids