Specification: Max Sound Output: 130+-5dB Level (SPL) +4db: 130db Maximum Acoustic Gain +db35 Equivalent Input Noice<30db Total Harmonic Wave Distortion<10% Working Voltage DCV 1.5 Operation current<4mA Battery AG3/A312 Note: 1.It is forbidden to use by those patients with tympanitis or ear pyogenesis. 2. Don t use it at high sound for 2. Don t use it at high sound for a long time. Otherwise, it will injure your ear. If you feel uncomfortable, please stop using. 3. Please maintain the products all the time avoid ear plug and sound collecting hole being blocked by foreign objects. It will affect the effect of the sound amplifier. 4. Avoid shocking, falling the product. Don t keep or use it in an environment of humid of high temperature. 5. Didn t throw the scrapped battery as common rubbish, it should be handled by special equipment. 6. Please take out the battery if don t use it for a long time. Otherwise, the components will be rotted by time rotten liquid from the battery. Please take out the battery if don t use it for a long time. Otherwise, the components will be rotted by time rotten liquid from the battery. 7. Don t use the products in potential explosive or dangerous environment. 8. Keep away from the children. It will injure him or others, or damage the unit. Accessory: 3 Different Size of Ear Tips HEARING AID AMPLIFIER1 x storage box3 Extra Batteries AG13